The following table summarizes the short-term borrowing activity for AWCC for the years ended December 31:
## Table 0 ##
The credit facility requires the Company to maintain a ratio of consolidated debt to consolidated capitalization of not more than 0.70 to 1.00.
The ratio as of December 31, 2017 was 0.59 to 1.00.
None of the Company’s borrowings are subject to default or prepayment as a result of a downgrading of securities, although such a downgrading could increase fees and interest charges under the Company’s credit facility.
As part of the normal course of business, the Company routinely enters contracts for the purchase and sale of water, energy, fuels and other services.
These contracts either contain express provisions or otherwise permit the Company and its counterparties to demand adequate assurance of future performance when there are reasonable grounds for doing so.
In accordance with the contracts and applicable contract law, if the Company is downgraded by a credit rating agency, especially if such downgrade is to a level below investment grade, it is possible that a counterparty would attempt to rely on such a downgrade as a basis for making a demand for adequate assurance of future performance.
Depending on the Company’s net position with the counterparty, the demand could be for the posting of collateral.
In the absence of expressly agreed provisions that specify the collateral that must be provided, the obligation to supply the collateral requested will be a function of the facts and circumstances of the Company’s situation at the time of the demand.
If the Company can reasonably claim that it is willing and financially able to perform its obligations, it may be possible that no collateral would need to be posted or that only an amount equal to two or three months of future payments should be sufficient.
The Company does not expect to post any collateral which will have a material adverse impact on the Company’s results of operations, financial position or cash flows.
Note 12: General Taxes The following table summarizes the components of general tax expense for the years ended December 31:
The following table summarizes the number of water and wastewater customers we served by class as of December 31:
## Table 1 ##
(a) In 2017, we acquired substantially all of the wastewater collection and treatment system assets of the Municipal Authority of the City of McKeesport, Pennsylvania (the “McKeesport system”).
This acquisition included approximately 22,000 customer equivalents in total; comprised of 11,000 customer connections, which are reflected in the 2017 residential customer count in the table above, as well as service to an additional 11,000 customers under bulk contracts to 13 municipalities in Allegheny County, Pennsylvania.
Customer growth in our Regulated Businesses is primarily driven by: (i) adding new customers to our customer base through acquisitions of water and/or wastewater utility systems; (ii) organic population growth (or decline) in our authorized service areas; and (iii) sale of water to other water utilities and community water systems.
Capital Investment On an annual basis, approximately 2 trillion gallons of treated water are lost in the United States through more than 240,000 main breaks at an estimated cost of $2.6 billion.
This represents approximately 20% of all treated water in the country.
In addition, every year approximately 900 billion gallons of untreated sewage is discharged into the country’s rivers and streams.
The aging water and wastewater infrastructure in the United States is in need of replacement and modernization.
In 2017, the American Society of Civil Engineers published its Report Card for America’s Infrastructure, in which it gave the drinking water industry a grade of “D” and the wastewater infrastructure a grade of “D+,” primarily because much of the infrastructure is nearing the end of its useful life.
As documented in the American Water Works Association’s (the “AWWA”) Buried No Longer: Confronting America’s Water Infrastructure Challenge, restoring the country’s existing water systems as they reach the end of their useful lives and expanding them to serve a growing population will cost at least $1 trillion between 2011 and 2035, if we are to maintain current levels of water service.
In addition, increased regulation related to water quality and the management of water and wastewater residuals’ discharges, which began with the passage of the Clean Water Act in 1972 and the Safe Drinking Water Act in 1974, is also a primary driver for the need to modernize.
To address the growing infrastructure needs in the areas we serve, we plan to invest $7.2 billion over the next five years, including a range of $1.4 billion to $1.5 billion in 2018, for capital improvements to our Regulated Businesses’ water and wastewater infrastructure, largely aimed for pipe replacement and upgrading aging water and wastewater treatment facilities.
We have proactively doubled our pipe renewal rate over a five year period, from 2011 to 2016, from a 250 year replacement cycle to a 120 year replacement cycle, which we anticipate will enable us to replace nearly 2,000 miles of mains and collection pipes over the next five years.
In addition, during this same five year period, capital investment in treatment plants, storage tanks and other key, above-ground facilities has increased over 10%, further addressing aging infrastructure and emerging regulatory compliance needs.
Economic Regulation and Rate Making Our Regulated Businesses operate under a regulatory compact whereby, in exchange for exclusive rights to provide water and wastewater services in defined service territories, we have an obligation to serve customers
ÿþOperation and Maintenance  The following table and ensuing discussions provide explanations for the variances related to the major  components of operation and maintenance expense:  @T@  In 2017, operation and maintenance expense decreased $35 million, or 9.
4%, primarily due to a:  "  $44 million decrease in operating supplies and services principally due to lower capital upgrades in our  Military Services Group in 2017, as discussed above, as well as lower advertising and marketing  expense in our Homeowners Services Group; partially offset by a  "  $3 million increase in employee-related costs largely attributable to higher headcount in Keystone due  to an increase in operations as a result of market recovery in the natural gas industry, offset in part in  our Contract Operations Group as several contracts were completed in 2017; and a  "  $5 million increase in other mainly due to an increase in customer uncollectible expense in our  Homeowner Services Group as a result of contract growth in 2017.
  In 2016, operation and maintenance expense increased $14 million, or 3.
9%, primarily due to a:  "  $11 million increase from Keystone, which was acquired in the third quarter of 2015, including  $8 million in employee-related costs and $1 million each in production costs, operating supplies and  services, and an;  "  $11 million increase in maintenance materials and supplies largely attributable to contract growth in  our Homeowner Services and Contract Operations Groups, and higher claims, marketing expenses and  costs associated with our investment in a new customer information system in our Homeowner  Services Group; and a  "  $10 million increase in employee-related costs principally due to the addition of the Vandenberg Air  Force Base contract in 2016, and increased headcount resulting from contract growth in our  Homeowner Services and Contract Operations Groups; partially offset by a  "  $18 million decrease in operating supplies and services mainly due to lower capital upgrades in our  Military Services Group, as discussed above.
  Liquidity and Capital Resources  We regularly evaluate and monitor our cash requirements for capital investments, acquisitions, operations,  commitments, debt maturities, interest and dividends.
 Our business is capital intensive, with a majority of this  capital funded by cash flows from operations.
 When necessary, we also obtain funds from external sources,  primarily in the debt markets and through short-term commercial paper borrowings.
 We also have access to  equity capital markets, if needed.
 Our access to external financing on reasonable terms depends on our credit  ratings and current business conditions, including that of the utility and water utility industries in general, as well  as conditions in the debt or equity capital markets, and the national and international economic and geopolitical
## Table 2 ##
The following table provides a summary of the major items affecting our cash flows provided by operating activities:

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td>2017</td><td>2016</td></tr><tr><td>Average borrowings</td><td>$779</td><td>$850</td></tr><tr><td>Maximum borrowings outstanding</td><td>1,135</td><td>1,016</td></tr><tr><td>Weighted average interest rates, computed on daily basis</td><td>1.24%</td><td>0.78%</td></tr><tr><td>Weighted average interest rates, as of December 31</td><td>1.61%</td><td>0.98%</td></tr></table>
<table><tr><td></td><td colspan="2">2017</td><td colspan="2">2016</td><td colspan="2">2015</td></tr><tr><td>(In thousands)</td><td>Water</td><td>Wastewater(a)</td><td>Water</td><td>Wastewater</td><td>Water</td><td>Wastewater</td></tr><tr><td>Residential</td><td>2,872</td><td>182</td><td>2,846</td><td>171</td><td>2,829</td><td>133</td></tr><tr><td>Commercial</td><td>221</td><td>11</td><td>220</td><td>10</td><td>219</td><td>8</td></tr><tr><td>Industrial</td><td>4</td><td>—</td><td>4</td><td>—</td><td>4</td><td>—</td></tr><tr><td>Public & other</td><td>63</td><td>—</td><td>61</td><td>—</td><td>60</td><td>—</td></tr><tr><td>Total</td><td>3,160</td><td>193</td><td>3,131</td><td>181</td><td>3,112</td><td>141</td></tr></table>
<table><tr><td></td><td colspan="3">For the Years Ended December 31,</td><td colspan="2" rowspan="2"Increase(Decrease) 2017 vs. 2016></td><td colspan="2" rowspan="2"Increase(Decrease) 2016 vs. 2015></td></tr><tr><td></td><td>2017</td><td>2016</td><td>2015</td></tr><tr><td>(Dollars in millions)</td><td></td><td></td><td></td><td>$</td><td>%</td><td>$</td><td>%</td></tr><tr><td>Production costs</td><td>$37</td><td>$35</td><td>$36</td><td>$2</td><td>5.7</td><td>$-1</td><td>-2.8</td></tr><tr><td>Employee-related costs</td><td>97</td><td>94</td><td>76</td><td>3</td><td>3.2</td><td>18</td><td>23.7</td></tr><tr><td>Operating supplies and services</td><td>121</td><td>165</td><td>182</td><td>-44</td><td>-26.7</td><td>-17</td><td>-9.3</td></tr><tr><td>Maintenance materials and supplies</td><td>67</td><td>68</td><td>57</td><td>-1</td><td>-1.5</td><td>11</td><td>19.3</td></tr><tr><td>Other</td><td>15</td><td>10</td><td>7</td><td>5</td><td>50.0</td><td>3</td><td>42.9</td></tr><tr><td>Total</td><td>$337</td><td>$372</td><td>$358</td><td>$-35</td><td>-9.4</td><td>$14</td><td>3.9</td></tr></table>

Question: What's the sum of the Production costs for For the Years Ended December 31, in the years where Residential for Water is greater than 0? (in million)
Answer: 108
Reasoning program: add(37,35), add(#0,36)