assumptions used to calculate fair value also included a three-year risk-free rate of 4.735%, dividend yields of 2.3% to 5.2% for the peer group, volatility of 12.91% to 18.33% for the peer group, and Ameren’s maintenance of its $2.54 annual dividend over the performance period.
Restricted Stock Restricted stock awards in Ameren common stock were granted under the 1998 Plan from 2001 to 2005.
Restricted shares have the potential to vest over a sevenyear period from the date of grant if the company achieves certain performance levels.
An accelerated vesting provision included in this plan reduces the vesting period from seven years to three years if the earnings growth rate exceeds a prescribed level.
Stock Options Ameren Options in Ameren common stock were granted under the 1998 Plan at a price not less than the fair-market value of the common shares at the date of grant.
Granted options vest over a period of five years, beginning at the date of grant, and they permit accelerated exercising upon the occurrence of certain events, including retirement.
There have not been any stock options granted since December 31, 2000.
Outstanding options of 85,800 at December 31, 2008, expire on various dates through 2010.
There is no expense from stock options for the years ended December 31, 2008, 2007 and 2006, as all options granted were fully vested.
NOTE 13 – INCOME TAXES The following table presents the principal reasons why the effective income tax rate differed from the statutory federal income tax rate for the years ended December 31, 2008, 2007 and 2006:
## Table 0 ##
(a) Permanent items are treated differently for book and tax purposes and primarily include Internal Revenue Code Section 199 production activity deductions for Ameren, UE, Genco, CILCORP and CILCO, company-owned life insurance for Ameren, CILCORP and CILCO, SFAS No.106-2 Medicare Part D for Ameren, UE, Genco, CILCORP and CILCO, employee stock ownership plan dividends for Ameren, and nondeductible expenses for IP.
(b) Primarily includes settlements with state taxing authorities for Ameren, state apportionment changes for Ameren, CIPS, Genco, CILCORP, and CILCO, research credits for Ameren, Genco, CILCORP, and CILCO and low-income housing tax credits for Ameren and CIPS.
(c) Primarily includes low-income housing tax credits for Ameren, UE, CIPS, Genco, CILCORP, and IP.
The following table presents electric and natural gas utility-related properties for UE, CIPS, CILCO and IP as of December 31, 2008:
## Table 1 ##
Our other properties include office buildings, warehouses, garages, and repair shops.
With only a few exceptions, we have fee title to all principal plants and other units of property material to the operation of our businesses, and to the real property on which such facilities are located (subject to mortgage liens securing our outstanding first mortgage bond and credit facility indebtedness and to certain permitted liens and judgment liens).
The exceptions are as follows: ‰ A portion of UE’s Osage plant reservoir, certain facilities at UE’s Sioux plant, most of UE’s Peno Creek and Audrain CT facilities, Genco’s Columbia CT facility, AERG’s Indian Trails generating facility, Medina Valley’s generating facility, certain of Ameren’s substations, and most of our transmission and distribution lines and gas mains are situated on lands we occupy under leases, easements, franchises, licenses or permits.
‰ The United States or the state of Missouri may own or may have paramount rights to certain lands lying in the bed of the Osage River or located between the inner and outer harbor lines of the Mississippi River on which certain of UE’s generating and other properties are located.
‰ The United States, the state of Illinois, the state of Iowa, or the city of Keokuk, Iowa, may own or may have paramount rights with respect to certain lands lying in the bed of the Mississippi River on which a portion of UE’s Keokuk plant is located.
Substantially all of the properties and plant of UE, CIPS, CILCO and IP are subject to the direct first liens of the indentures securing their mortgage bonds.
In July 2006 and February 2007, AERG recorded open-ended mortgages and security agreements with respect to its E. D.  Edwards and Duck Creek power plants.
These plants serve as collateral to secure its obligations under multiyear, senior secured credit facilities entered into on July 14, 2006, and February 9, 2007, along with other Ameren subsidiaries.
See Note 4 – Short-term Borrowings and Liquidity under Part II, Item 8, of this report for details of the credit facilities.
UE has conveyed most of its Peno Creek CT facility to the city of Bowling Green, Missouri, and leased the facility back from the city through 2022.
Under the terms of this capital lease, UE is responsible for all operation and maintenance responsibilities for the facility.
Ownership of the facility will transfer to UE at the expiration of the lease, at which time the property and plant will become subject to the lien of any outstanding UE first mortgage bond indenture.
In March 2006, UE purchased a CT facility located in Audrain County, Missouri, from NRG Audrain Holding, LLC, and NRG Audrain Generating LLC, both affiliates of NRG Energy, Inc.  (collectively, NRG).
As a part of this transaction, UE was assigned the rights of NRG as lessee of the CT facility under a long-term lease with Audrain County and assumed NRG’s obligations under the lease.
The lease term will expire on December 1, 2023.
Under the terms of this capital lease, UE has all operation and maintenance responsibilities for the facility, and ownership of the facility will be transferred to UE at the expiration of the lease.
When ownership of the Audrain County CT facility is transferred to UE by the county, the property and plant will become subject to the lien of any outstanding UE first mortgage bond indenture.
See Note 15 – Commitments and Contingencies to our financial statements under Part II, Item 8, of this report for information on mechanics’ liens filed against CILCO’s Duck Creek plant.
ITEM 3.
LEGAL PROCEEDINGS.
We are involved in legal and administrative proceedings before various courts and agencies with respect to matters that arise in the ordinary course of business, some of which involve substantial amounts of money.
We believe that the final disposition of these proceedings, except as otherwise disclosed in this report, will not have a material adverse effect on our results of operations, financial position, or liquidity.
Risk of loss is mitigated, in some cases, by insurance or contractual or statutory indemnification.
We believe that we have established appropriate reserves for potential losses.
For additional information on legal and administrative proceedings, see Rates and Regulation under Item 1, Business, and Item 1A, Risk Factors, above.
See also Liquidity and Capital Resources and Regulatory Matters in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, and Note 2 – Rate and Regulatory Matters, and Note 15 – Commitments and Contingencies to our financial statements under Part II, Item 8, of this report.
ITEM 4.
SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.
There were no matters submitted to a vote of security holders during the fourth quarter of 2008 with respect to any of the Ameren Companies.
MARATHON OIL CORPORATION Notes to Consolidated Financial Statements 7.
Dispositions Outside-operated Norwegian properties – On October 31, 2008, we closed the sale of our Norwegian outside-operated properties and undeveloped offshore acreage in the Heimdal area of the Norwegian North Sea for net proceeds of $301 million, with a pretax gain of $254 million as of December 31, 2008.
Pilot Travel Centers – On October 8, 2008, we completed the sale of our 50 percent ownership interest in PTC.
Sale proceeds were $625 million, with a pretax gain on the sale of $126 million.
Immediately preceding the sale, we received a $75 million partial redemption of our ownership interest from PTC that was accounted for as a return of investment.
Operated Irish properties – On December 17, 2008, we agreed to sell our operated properties located in Ireland for proceeds of $180 million, before post-closing adjustments and cash on hand at closing.
Closing is subject to completion of the necessary administrative processes.
As of December 31, 2008, operating assets and liabilities were classified as held for sale, as disclosed by major class in the following table:
## Table 2 ##
8.
Discontinued Operations On June 2, 2006, we sold our Russian oil exploration and production businesses in the Khanty-Mansiysk region of western Siberia.
Under the terms of the agreement, we received $787 million for these businesses, plus preliminary working capital and other closing adjustments of $56 million, for a total transaction value of $843 million.
Proceeds net of transaction costs and cash held by the Russian businesses at the transaction date totaled $832 million.
A gain on the sale of $243 million ($342 million before income taxes) was reported in discontinued operations for 2006.
Income taxes on this gain were reduced by the utilization of a capital loss carryforward.
Exploration and Production segment goodwill of $21 million was allocated to the Russian assets and reduced the reported gain.
Adjustments to the sales price were completed in 2007 and an additional gain on the sale of $8 million ($13 million before income taxes) was recognized.
The activities of the Russian businesses have been reported as discontinued operations in the consolidated statements of income and the consolidated statements of cash flows for 2006.
Revenues applicable to discontinued operations were $173 million and pretax income from discontinued operations was $45 million for 2006.

<table><tr><td></td><td>Ameren</td><td>UE</td><td>CIPS</td><td>Genco</td><td>CILCORP</td><td>CILCO</td><td>IP</td></tr><tr><td> 2008:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Statutory federal income tax rate:</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td></tr><tr><td>Increases (decreases) from:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Permanent items<sup>(</sup><sup>a</sup><sup>)</sup></td><td>-1</td><td>1</td><td>-1</td><td>-2</td><td>-3</td><td>-1</td><td>7</td></tr><tr><td>Depreciation differences</td><td>-</td><td>-1</td><td>-2</td><td>-</td><td>-1</td><td>-1</td><td>-</td></tr><tr><td>Amortization of investment tax credit</td><td>-1</td><td>-1</td><td>-10</td><td>-</td><td>-1</td><td>-1</td><td>-</td></tr><tr><td>State tax</td><td>4</td><td>3</td><td>5</td><td>5</td><td>4</td><td>5</td><td>5</td></tr><tr><td>Reserve for uncertain tax positions</td><td>-1</td><td>-1</td><td>-1</td><td>-1</td><td>1</td><td>-</td><td>2</td></tr><tr><td>Other<sup>(</sup><sup>b</sup><sup>)</sup></td><td>-2</td><td>-</td><td>-1</td><td>-1</td><td>-4</td><td>-1</td><td>1</td></tr><tr><td>Effective income tax rate</td><td>34%</td><td>36%</td><td>25%</td><td>36%</td><td>31%</td><td>36%</td><td>50%</td></tr><tr><td> 2007:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Statutory federal income tax rate:</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td></tr><tr><td>Increases (decreases) from:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Permanent items<sup>(</sup><sup>a</sup><sup>)</sup></td><td>-2</td><td>-2</td><td>2</td><td>-1</td><td>-5</td><td>-2</td><td>1</td></tr><tr><td>Depreciation differences</td><td>-</td><td>-</td><td>3</td><td>-</td><td>-2</td><td>-1</td><td>-3</td></tr><tr><td>Amortization of investment tax credit</td><td>-1</td><td>-1</td><td>-6</td><td>-1</td><td>-2</td><td>-1</td><td>-</td></tr><tr><td>State tax</td><td>4</td><td>4</td><td>6</td><td>5</td><td>3</td><td>3</td><td>5</td></tr><tr><td>Reserve for uncertain tax positions</td><td>-1</td><td>-1</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Other<sup>(</sup><sup>c</sup><sup>)</sup></td><td>-1</td><td>-2</td><td>-4</td><td>-</td><td>1</td><td>-</td><td>-1</td></tr><tr><td>Effective income tax rate</td><td>34%</td><td>33%</td><td>36%</td><td>38%</td><td>30%</td><td>34%</td><td>37%</td></tr><tr><td> 2006:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Statutory federal income tax rate:</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td><td>35%</td></tr><tr><td>Increases (decreases) from:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Permanent items<sup>(</sup><sup>a</sup><sup>)</sup></td><td>-2</td><td>-2</td><td>-</td><td>-4(d)</td><td></td><td>-5</td><td>1</td></tr><tr><td>Sales of noncore properties</td><td>-2</td><td>-</td><td>-</td><td>-(d)</td><td></td><td>-2</td><td>-</td></tr><tr><td>Nondeductible expenses</td><td>1</td><td>2</td><td>-</td><td>-(d)</td><td></td><td>-</td><td>-</td></tr><tr><td>Depreciation differences</td><td>1</td><td>2</td><td>-5</td><td>-(d)</td><td></td><td>-3</td><td>-</td></tr><tr><td>Amortization of investment tax credit</td><td>-1</td><td>-1</td><td>-3</td><td>-1(d)</td><td></td><td>-2</td><td>-</td></tr><tr><td>State tax</td><td>4</td><td>3</td><td>5</td><td>5(d)</td><td></td><td>5</td><td>5</td></tr><tr><td>Reserve for uncertain tax positions</td><td>-1</td><td>-</td><td>-2</td><td>-2(d)</td><td></td><td>-11</td><td>-</td></tr><tr><td>Other<sup>(</sup><sup>c</sup><sup>)</sup></td><td>-2</td><td>-1</td><td>-1</td><td>-2(d)</td><td></td><td>-</td><td>-1</td></tr><tr><td>Effective income tax rate</td><td>33%</td><td>38%</td><td>29%</td><td>31%(d)</td><td></td><td>17%</td><td>40%</td></tr></table>
<table><tr><td></td><td>UE</td><td>CIPS</td><td>CILCO</td><td> IP</td></tr><tr><td>Circuit miles of electric transmission lines</td><td>2,942</td><td>2,306</td><td>331</td><td>1,853</td></tr><tr><td>Circuit miles of electric distribution lines</td><td>32,956</td><td>14,931</td><td>8,853</td><td>21,607</td></tr><tr><td>Circuit miles of electric distribution lines underground</td><td>22%</td><td>11%</td><td>25%</td><td>12%</td></tr><tr><td>Miles of natural gas transmission and distribution mains</td><td>3,232</td><td>5,338</td><td>3,907</td><td>8,770</td></tr><tr><td>Propane-air plants</td><td>1</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Underground gas storage fields</td><td>-</td><td>3</td><td>2</td><td>7</td></tr><tr><td>Billion cubic feet of total working capacity of underground gas storage fields</td><td>-</td><td>2</td><td>8</td><td>15</td></tr></table>
<table><tr><td><i>(In millions)</i></td><td>2008</td></tr><tr><td>Current assets</td><td>$164</td></tr><tr><td>Noncurrent assets</td><td>103</td></tr><tr><td>Total assets</td><td>267</td></tr><tr><td>Current liabilities</td><td>62</td></tr><tr><td>Noncurrent liabilities</td><td>199</td></tr><tr><td>Total liabilities</td><td>261</td></tr><tr><td>Net assets held for sale</td><td>$6</td></tr></table>

Question: What's the increasing rate of state tax of UE in 2008 ? (in %)