1

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

MEMORANDUM

DATE: July 22, 2010

SUBJECT: Estimated Drinking Waters Concentrations (EDWCs) of Triflusulfuron-methyl

for the Use in the Human Health Risk Assessment: New Use (IR-4) of the 

Chemical on Garden Beets (PC Code 129002; DP Barcode D373494)

TO: Laura Nollen, Risk Manager Reviewer

Barbara Madden, Review Manager #5

Daniel (Dan) Rosenblatt, Chief

Minor Use Team

Risk Integration, Minor Use, and Emergency Response Branch

Registration Division (7505P)

AND: Elizabeth Holman, Chemist, Risk Assessor

Linnea Hansen, Risk Assessor

Christina Swartz, Chief

Registration Action Branch II

Health Effects Division (7509P)

FROM: José L. Meléndez, Chemist

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

THRU: Mah T. Shamim, Ph.D., Chief

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

This memo presents the surface and ground Estimated Drinking Water Concentrations 

(EDWCs) for triflusulfuron-methyl, calculated using the Tier 2 aquatic models PRZM/ EXAMS 

and the Tier 1 aquatic model SCI-GROW, respectively, for use in the human health risk 

assessment. The registrant is proposing the use of the chemical on garden beets. Based on an 

inspection of the new use of triflusulfuron-methyl, it was found that sugar beet still represents the

scenario with the highest exposure. The previously modeled use covers the new use. Therefore, 
2

the drinking waters assessment results do not change from the previous ones. For electronic 

copy of the previous drinking waters assessment refer to DP Barcode D260078 (Attachment A, 

see page 3 of this document).

The EDWCs for triflusulfuron-methyl, calculated using the Tier 2 models PRZM/

EXAMS (surface water) and the Tier 1 model SCI-GROW (ground water) for use in the human 

health risk assessment were as follows: In surface waters, the acute value is 0.42 ppb and the 

chronic value is 0.005 ppb. The groundwater screening concentration of triflusulfuron-methyl

suitable for both acute and chronic exposures is 0.50 ppb (Table 1). Should any questions arise, 

please, contact EFED.

Table 1. Estimated Drinking Water Concentrations (EDWCs) for human health risk assessment 

for aerial application of triflusulfuron-methyl on sugar beets

Chemical

Acute Surface Water 

PRZM/EXAMS (ppb)

Chronic Surface Water 

PRZM/EXAMS (ppb)

Acute and Chronic Ground Water 

SCI-GROW (ppb)*

Triflusulfuronmethyl 0.42 0.005 0.50

Identification of data gaps:

Additional aerobic and anaerobic soil studies and aerobic and anaerobic aquatic 

metabolism studies would decrease substantially the uncertainties in the fate database.

Use Characterization

Table 2 provides a summary of the new use proposed in this action for triflusulfuronmethyl, as well as the approved uses for the chemical. The use information was obtained from

the current and proposed supplemental label for DuPontTM UpBeet® Herbicide (EPA Reg. No. 

352-569). DuPontTM UpBeat® is a water dispersible granule (dry flowable) formulation, 

containing 50% active ingredient.

Table 2. Summary of use information for triflusulfuron-methyl, based on the proposed label for DuPontTM 

UpBeet® Herbicide (EPA Reg. No. 352-569). The new use is shaded yellow and bolded.

USE

SINGLE 

APP. RATE 

(lb a.i./A)

NUMBER 

OF APPS.

SEASONAL 

APP. RATE 

(lb a.i./A)

INTERVAL 

BETWEEN 

APPS. (days)

APP. 

METHOD

INCORP.

DEPTH 

(inches) PHI

Garden beets 0.0156 3 0.0469 NS1 G or A

2

0

2

602

Sugar beets (includes those 

grown for seeds)

0.0156-

0.0313;

0.003913

2-3 0.0781 5 G or A 0 60

Belgian Endive/Chicory 0.0156 2-3 0.0469 5 G or A20

2

60

1 Not specified. Apply at 2 to 4 leaf stage; additional applications at 4 to 6 and 6 to 8 leaf stages.

2

Per reference to Section 3 label in the Supplemental Label and instructions provided in the package.

3 Microrate applications (make a minimum of 3 applications).
3

Attachment A. Electronic copy of previous DWA for Triflusulfuron-methyl

 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

 WASHINGTON, D.C. 20460

 OFFICE OF

 PREVENTION, PESTICIDES AND

 TOXIC SUBSTANCES 

December 20, 1999

DP Barcode: D260078

PC Code: 129002

MEMORANDUM

Subject: Triflusulfuron-Methyl Tier II Estimated Environmental Concentrations for Use in 

the Human Health Drinking Water Risk Assessment

Product: UpBeet Water Dispersible Granule (50% Active); 352-569

Registrant: DuPont

To: Michael Doherty 

Registration Action Branch 2

Health Effects Division (7509C)

Vickie Walters, Product Manager

Herbicide Branch

Registration Division (7505C)

From: Sid Abel, Environmental Scientist

Fate and Monitoring Branch

Environmental Fate and Effects Division (7507C)

Thru: Betsy Behl, Chief

 Fate and Monitoring Branch

Environmental Fate and Effects Division (7507C)

This memorandum transmits the Tier II Estimated Environmental Concentrations (EECs) 

for the tolerance reassessment of triflusulfuron-methyl applied to sugarbeets using the Index 

Reservoir (IR) and Percent Crop Area (PCA) modifications to PRZM and EXAMS. These 

results do not include EECs for any of triflusulfuron-methyl’s known degradates. Should HED 

determine that there is a need for a separate assessment for toxicologically significant degradates, 

please contact Sid Abel (305-7346) as soon as possible.
4

Summary and Conclusions

Triflusulfuron-methyl may be found in surface water used as a source of drinking water 

at peak concentrations up to 0.42 μg/L and on a long-term basis (mean) at 0.005 μg/L from use 

on sugarbeets in Minnesota. Ground water concentrations, independent of the use area, may be 

found at up to 0.5 μg/L; peak and mean concentrations. Triflusulfuron-methyl will not persist in 

the environment (accumulate between repeated yearly applications) due to its short initial halflife (bi-phasic) and hydrolytic half-life at environmental pH’s. The low adsorption coefficients 

may facilitate triflusulfuron’s leaching to ground water under favorable conditions (shallow 

depth to groundwater, coarse soils, or soils with significant preferential flow). Due to 

triflusulfuron-methyl’s structure and physical properties, it is not likely to be significantly

affected by common treatment methods employed at most community water systems (Faust, 

1998). 

Triflusulfuron-methyl is currently registered for use on sugarbeets. Estimated 

environmental concentrations for sugarbeets are provided Table 1. These estimated values are 

recommended for use in the drinking water assessment.

Table 1. Recommended Surface and Ground Water Concentrations ( μg/L)

Agricultural Setting Surface Water Concentrations Ground Water Concentrations

Sugarbeets Grown in 

Minnesota

Peak Mean 0.50

0.42 0.005

Environmental Fate Summary

Triflusulfuron-methyl is not a very persistent sulfonylurea herbicide. The principle 

pathway of dissipation in the environment is through aerobic and anaerobic metabolism 

and to a lesser degree hydrolysis. Direct photolysis on soil and in water is not a very 

important pathway, but indirect photolysis may play a minor role in its degradation on 

soils. Biotically, Triflusulfuron-methyl degradation follows a bi-phasic pattern with an 

approximate soil half-life of 6 days initially, followed by a secondary half-life of 

approximately 170 days in aerobically incubated soil. Under anaerobic soil conditions, 

triflusulfuron-methyl degraded with a half-life of 20 days. Triflusulfuron-methyl is mobile 

in all soils tested; Kd’s less than 1.3. However, the parent was not detected below 14 inches 

in the two field dissipation studies and decreased in concentration over the period of the 

study indicating biotic degradation. Sorption was not well correlated to organic matter, 

but was better correlated to the soil pH.

Triflusulfuron-methyl degrades through cleavage of the sulfonylurea bridge to form 

degradates containing either the triazine or phenyl ring. The principle degradates seen in 

the laboratory studies is methyl saccharin and various triazine amines. Methyl saccharin is 

more mobile than the parent with Kd’s all less than 1.0 (KOC’s <25). In several of the soils, 

binding was so low that analysis could not be performed to determine the extent of binding. 
5

The half-life of methyl saccharin is 50-days under aerobic conditions and further degrades 

via mineralization. The other major degradates, triazine-amines, are less mobile than the 

parent. Among the triazine-amines, mobility increases with a higher degree of 

demethylation. The bis-NDM-triazine amine is the most mobile with Kd’s up to 3.72 (KOC’s

<220) and the least mobile, triazine-amine, had Kd’s up to 10 (KOC’s <2175). For NDMtriazine-amine, Kd’s were up to 4.88 (KOC’s <300). The half-life of triazine amine is 

approximately 40 days and further degrades by demethylation. Both degradates were 

detected up to the 36-inch segment in one or both of the field dissipation studies. 

Concentrations of methyl saccharin and triazine amine were very similar during the 

studies and dissipated with very similar patterns. 

Water Resources Summary: Drinking Water

A. Surface Water

PRZM/EXAMS modeling using the Index Reservoir (IR) and the Percent Crop Area 

(PCA) adjustment was used to estimate concentrations in surface water used as a source of 

drinking water. The index reservoir represents a watershed that is more vulnerable than most 

used as drinking water sources. It was based on characteristics of a real watershed located in 

western Illinois (Jones, et al., 1998). The index reservoir defines a standardized watershed 

which is tailored for each crop simulated by adding local soils, weather, and cropping practices 

to represent a vulnerable watershed for that crop. If a community derives its drinking water from 

a large river, the estimated exposure using the IR would likely be higher than the actual 

exposure. Conversely, a community that derives its drinking water from reservoirs smaller than 

the IR and/or with minimal outflow would likely get higher drinking water exposure than 

estimated using the index reservoir. Also, areas with a more humid climate than the modeled 

scenario that use a similar reservoir and cropping pattern, would likely have higher pesticide 

concentrations in their drinking water than predicted.

Transport through the reservoir is represented by a single steady flow and does not take 

into account reservoir discharges and withdrawals. This assumption will underestimate removal 

from the reservoir during wet periods and overestimate removal during dry periods. The index 

reservoir scenario uses the characteristic of a single soil to represent all soils in the basin. Soils 

can vary substantially across even small areas, however, this variation is not reflected in these 

simulations. 

The index reservoir scenario does not take into account pesticide or water input from tile 

drainage. Areas that are prone to substantial runoff are often tile drained. This may

underestimate exposure, particularly on a chronic basis (the watershed on which the IR is based 

had no documented tile drainage). Additionally, EXAMS is unable to easily model spring and 

fall turnover events which results in complete mixing of a chemical through the water column. 

Because of this inability, Shipman City Lake has been simulated without stratification. There is 

data to suggest that Shipman City Lake does stratify in the deepest parts of the lake at least in 

some years. This may result in both an over and underestimation of the concentration in 
6

drinking water depending upon the time of the year and the depth the drinking water intake is 

drawing from. A full description of the Index Reservoir and assumptions is provided in the 

“Guidance for Use of the Index Reservoir in Drinking Water Exposure Assessment” available 

from EFED upon request.

Development of a Percent Crop Area (PCA), watershed-based adjustment factor for the 

percent of land in production for a specific crop, for sugarbeets has not been performed. The 

SAP recommended against the use of the PCA for ‘minor’ crops because it believed that the 

scale of the watershed size used to develop the PCA was too large and the resulting PCAs would 

likely be highly inaccurate and not conservative. In the absence of a PCA for sugarbeets, a 

default PCA of 0.9 is currently being used. This is based on the highest PCA for all 8-digit 

HUCs in the coterminous U.S. was selected for the default PCA. This value is 90 percent (0.9); 

representing a basin where 90 percent of the land area is in some form of agricultural production.

Tier 2 modeling with the index reservoir and the PCA is intended for use as a screen. 

That is, the estimated concentration should be higher than most values that occur in areas where 

a particular crop is grown. A preliminary assessment comparing monitoring data for a few 

chemicals to estimates made using these methods indicate that IR/PCA estimates may not be 

consistently conservative. However, monitoring data at drinking water facilities is sparsely

available and we are unable to check the validity for most crops against monitoring data at this 

time.

Additional inherent limitations in the data used to develop the PCA include:

• The conversion of county-level data to watershed-based percent crop areas assume the 

distribution of the crops within a county is uniform and homogeneous. Distance between 

the treated fields and the water body is not taken into account.

• The PCA’s were generated using 1992 Census of Agriculture. However, recent changes 

in the agriculture sector from farm bill legislation may significantly impact the 

distribution of crops throughout the country. Therefore, the approach assumes that yearto-year variation in cropping patterns are minimal, thus, have minimal impacts.

The results of the modeling are presented in Table 2 and the pesticide-specific parameters 

used to model sugarbeets are provided in Table 3. Appendix A provides the scenario specific 

inputs for PRZM and EXAMS. A brief description of the modeled site follows.

The field used to grow sugarbeets is located in Polk County, Minnesota. The soil is a 

Bearden silty clay loam; a fine-silty, mixed, superactive, frigid Aeric Calciaquolls. The 

series consists of very deep, somewhat poorly drained, moderate to slowly permeable soil 

that formed in calcareous silt loam and silty clay loam lacustrine sediments. These soils 

are on glacial lake plains and have slopes of 0 to 3 percent. Mean annual precipitation is 

about 18 inches. The series is of large extent in eastern North Dakota and northwestern 
7

Minnesota. These soils are nearly all cropped to small grains and row crops such as 

sugarbeets. The Bearden soil is characterized as a Hydrologic Group C soil.

Table 2. PRZM/EXAMS Estimated Surface Water Concentrations (μg/L)

Agricultural Setting

Estimated 1 in 10 Year 

Peak Estimated 1 in 10 Year Mean

Sugarbeets Grown in 

Minnesota

0.42 0.005

Table 3. Triflusulfuron-methyl Specific PRZM/EXAMS Input Parameters

Input Parameter Input Value Data Source

Hydrolysis pH 5: 3.7 days

pH 7: 32 days

pH 9: 36 days

MRID 4249859

Photolysis (soil and water) Stable MRIDs 42991424; 

42991426

Aerobic Soil Metabolism (T1/2) Bi-Phasic: 6 days, 170 

days

MRID 42496860

Soil Adsorption Coefficient (L/Kg) 0.41 MRID 42496861

Solubility (μg/L) 110 EFED One-Liner

Henry’s Law Coefficient (atm. m3/mole 5.9E-10 EFED Estimated

Vapor Pressure (torr) 1.0E-7 EFED One-Liner

Application Rate (kg/ha) 0.035 Label: UpBeet

Number of Application and Method 2; aerial Label: UpBeet

B. Ground Water

Ground water EEC were modeled using SCI-GROW, a screening groundwater regression 

model developed using data from prospective groundwater studies submitted to the OPP in 

support of registration. SCI-GROW provides a reasonable high-end estimate of ground water 

concentrations of pesticides within a defined set of fate and transport characteristics on soils that 
8

are known to be vulnerable to pesticide leaching (high sand content with shallow depth to 

groundwater).

Table 4 provides the fate inputs and ground water concentration for the application rate 

and interval listed in Table 3. The estimated EEC is considered representative of both a peak and 

long-term average concentration because of the inherent transport nature of ground water 

(generally slow movement from source of contamination both laterally and horizontally).

Table 4. SCI-GROW Estimated Ground Water Concentrations ( μg/L)

Agricultural 

Setting 

Fate and Transport Inputs

Concentration in 

Ground Water (μg/L)

Aerobic Soil 

Metabolism (T1/2) 

Soil Adsorption 

Coefficient (L/Kg)

Sugarbeets 170 0.50 0.50

REFERENCES

Faust, S.D. and O.M. Aly. 1998. “Chemistry of Drinking Water Treatment.” 2nd Edition 

Revised, CRC Press LLC. July, 1998.

Jones, R.D., S.W. Abel, W. Effland, R. Matzner, and R. Parker. 1998. “An Index Reservoir for 

Use in Assessing Drinking Water Exposures. Chapter IV in Proposed Methods for BasinScale Estimation of Pesticide Concentrations in Flowing Water and Reservoirs for 

Tolerance Reassessment., presented to the FIFRA Science Advisory Panel, July 29, 1998. 

http://www.epa.gov/pesticides/SAP/1998/index.htm
9

APPENDIX A

Table A-1 PRZM 3.12 Climate and time parameters for Minnesota Sugarbeets.

Minnesota Potatoes

Parameter Value Source Quality

Starting Date*January 1, 1948

Ending Date* December 31, 1983

Pan Evaporation Factor (PFAC) 0.760 PIC good

Snowmelt Factor (SFAC) 0.500 cm  K

-1 PIC good

Minimum Depth of

Evaporation (ANETD)

12.0 cm PIC good

* These values are in the RUN file rather than the INP file.

Table A-2. Erosion and landscape parameters for Minnesota Sugarbeets.

Minnesota Potatoes

Parameter Value Source Quality

USLE K Factor

(USLEK)

0.28 tons EI-1* PIC good

USLE LS Factor (USLELS) 0.12 PIC fair

USLE P Factor (USLEP) 0.50 ** fair

Field Area (AFIELD) 172.8 ha Index Reservoir good

NRCS Hyetograph (IREG) 3 good

Slope (SLP) 3.0% Official Soil 

Description***

fair

Hydraulic Length (HL) 464 m Index Reservoir good

* EI = 100 ft-tons * in/ acre*hr

** P Factor represent compromise for 1 year of conventional tillage and two years of no till.

*** OSD located at http://www.statlab.iastate.edu/soild/osd.
10

 Table A-3. PRZM 3.1 crop parameters for Minnesota Sugarbeets.

Minnesota Potatoes

Parameter Value Source Quality

Initial Crop (INICRP) 1 PIC good

Initial Surface Condition (ISCOND) 3 PIC fair

Number of Different Crops (NDC) 1 ** fair - good

Number of Cropping Periods 

(NCPDS)

36 Standard

Maximum rainfall interception 

storage of crop (CINTCP)

0.10 PIC fair

Maximum Active Root Depth 

(AMXDR)

20 cm PIC fair

Maximum Canopy Coverage 

(COVMAX)

80 PIC fair

Soil Surface Condition After Harvest 

(ICNAH)

3 PIC fair

Date of Crop Emergence

(EMD, EMM, IYREM)

05/16 fair - good

Date of Crop Maturity

(MAD, MAM, IYRMAT)

10/06 fair - good

Date of Crop Harvest (HAD, 

HAM,IYRHAR)

10/16 fair - good

Maximum Dry Weight (WFMAX) 0.0 PIC fair

SCS Curve Number (CN) 82-91 PIC fair

Manning’s N Value (MNGN) 0.020 PRZM Manual good

USLE C Factor (USLEC) 0.18-0.43 PIC fair

** P Factor represent compromise for 1 year of conventional tillage and two years of no till.
11

Table A-4. PRZM 3.1 soil parameters for Bearden silty clay used for sugarbeets in Polk County, Minnesota.

Parameter Value Source Quality

Total Soil Depth (CORED) 100 cm PIC good

Number of Horizons (NHORIZ) 4 PIC good

First, Second, Third, and Fourth Soil Horizons (HORIZN = 1, 2, 3, 4)

Horizon Thickness (THKNS) 10 cm (HORIZN = 1)

08 cm (HORIZN = 2)

54 cm (HORIZN = 3)

28 cm (HORIZN = 4)

PIC good

Bulk Density (BD) 1.40 g cm-3

(HORIZN = 1, 2)

1.50 g cm-3(HORIZN = 3)

1.80 g cm-3(HORIZN = 4)

PIC good

Initial Water Content (THETO) 0.377 cm3

-H2O cm3-soil 

(HORIZN = 1, 2)

0.292 cm3-H2O cm3-soil 

(HORIZN = 3)

0.285 cm3-H2O cm3-soil 

(HORIZN = 4)

PIC good

Compartment Thickness (DPN) 0.1 cm (HORIZN = 1)

1.0 cm (HORIZN = 2)

2.0 cm (HORIZN = 3, 4)

standard

Field Capacity (THEFC) 0.377 cm3

-H2O cm3-soil 

(HORIZN = 1, 2)

0.2292cm3-H2O cm

3

-soil 

(HORIZN = 3)

0.285 cm3-H2O cm3-soil 

(HORIZN = 4)

PIC good

Wilting Point 0.207 cm3

-H2O cm3-soil 

(HORIZN = 1, 2)

0.132 cm3-H2O cm3-soil 

(HORIZN = 3)

0.125 cm3-H2O cm3-soil 

(HORIZN = 4)

PIC good

Organic Carbon Content 1.16% (HORIZN = 1, 2, 3)

0.174% (HORIZN = 4)

PIC good
12

Table A-5. PRZM 3.1 model state flags for modeled scenario.

Parameter Value

Pan Factor Flag (IPEIND) 0

Foliar Application Model Flag (CAM) 2

Bulk Density Flag (BDFLAG) 0

Water Content Flag (THFLAG) 0

Kd Flag (KDFLAG) 0

Drainage model flag (HSWZT) 0

Method of characteristics flag (MOC) 0

Irrigation Flag (IRFLAG) 0

Soil Temperature Flag (ITFLAG) 0

Thermal Conductivity Flag (IDFLAG) 0

Biodegradation Flag (BIOFLAG) 0

Erosion Calculation Flag (ERFLAG) 4

Table A-6. EXAMS II geometry for Index Reservoir.

Littoral Benthic Source

Area (AREA) 52,609 m252,609 m2Jones et al., 1998

Depth (DEPTH) 2.74 m 0.05 m Jones et al., 1998

Volume (VOL) 144,000 m32630 m

3

Jones et al., 1998

Length (LENG) 640 m 640 m estimated from map 

Width (WIDTH) 82.2 m 82.2 m estimated from map

Stream Flow 

(STFLO)

Minnesota 

Reservoir

12.25 m3h

-1

0 m3h

-1

see guidance†

†Guidance for Use of the Index Reservoir in Drinking Water Exposure Assessments, Jones, et al. 

November 16, 1999.
13

Table A-7. EXAMS II dispersive transport parameters between benthic and littoral layers in the Index 

Reservoir.

Parameter Path 1*Source

Turbulent Cross-section (XSTUR) 52609 m

2 Burns, 1997

Characteristic Length (CHARL) 1.395 m Burns, 1997

Dispersion Coefficient for Eddy Diffusivity (DSP)** 3.0 x 10-5standard pond

*

JTURB(1) = 1, ITURB(1) = 2; ** each monthly parameter set to this value.

Table A-8. EXAMS II sediment properties for the Index Reservoir.

Parameter Littoral Benthic Source

Suspended Sediment (SUSED) 30 mg L-1standard pond

Bulk Density (BULKD) 1.85 g cm-3standard pond

Per cent Water in Benthic Sediments (PCTWA) 137% standard pond

Fraction of Organic Matter (FROC) 0.04 0.04 standard pond

Table A-9. EXAMS II external environmental and location parameters for the Index 

Reservoir.

Parameter Value Source

Precipitation (RAIN) 0 mm 

month-1

Atmospheric Turbulence (ATURB) 2.00 km standard pond

Evaporation Rate (EVAP) 0 mm 

month-1

Wind Speed (WIND) 1 m sec-1standard pond

Air Mass Type (AMASS) Rural (R)

Elevation (ELEV) 54.9 m USGS map

Latitude (LAT) 39.12o N USGS map

Longitude (LONG) 90.05o W USGS map
14

Table A-10. EXAMS II biological characterization parameters for the Index Reservoir.

Parameter Limnic Benthic Source

Bacterial Plankton Population Density (BACPL) 1 cfu cm-3see text

Benthic Bacteria Population Density (BNBAC) 37 cfu (100 g)-1see text

Bacterial Plankton Biomass (PLMAS) 0.40 mg L

-1

standard pond

Benthic Bacteria Biomass (BNMAS) 6.0x10-3

g m

-2

standard pond

Table A-11. EXAMS water quality parameters for the Index Reservoir.

Parameter Value Source

Optical path length distribution factor (DFAC) 1.19 Standard pond

Dissolved organic carbon (DOC) 5 mg L

-1

standard pond

chlorophylls and pheophytins (CHL) 5x10-3 mg L

-1

standard pond

pH (PH) 7 standard pond

pOH (POH) 7 standard pond

Table A-12. EXAMS mean monthly water 

temperatures (TCEL) for the Index Reservoir.

Month Temperature (Celsius)

January 0

February 1.09

March 6.26

April 13.21

May 18.61

June 23.73

July 26.09

August 25.04

September 20.91

October 14.5

November 7.04

December 0.99