Goodwill is reviewed annually during the fourth quarter for impairment.
In addition, the Company performs an impairment analysis of other intangible assets based on the occurrence of other factors.
Such factors include, but are not limited to, significant changes in membership, state funding, medical contracts and provider networks and contracts.
An impairment loss is recognized if the carrying value of intangible assets exceeds the implied fair value.
Medical Claims Liabilities Medical services costs include claims paid, claims reported but not yet paid, or inventory, estimates for claims incurred but not yet received, or IBNR, and estimates for the costs necessary to process unpaid claims.
The estimates of medical claims liabilities are developed using standard actuarial methods based upon historical data for payment patterns, cost trends, product mix, seasonality, utilization of healthcare services and other relevant factors including product changes.
These estimates are continually reviewed and adjustments, if necessary, are reflected in the period known.
Management did not change actuarial methods during the years presented.
Management believes the amount of medical claims payable is reasonable and adequate to cover the Company’s liability for unpaid claims as of December 31, 2006; however, actual claim payments may differ from established estimates.
Revenue Recognition The Company’s Medicaid Managed Care segment generates revenues primarily from premiums received from the states in which it operates health plans.
The Company receives a fixed premium per member per month pursuant to our state contracts.
The Company generally receives premium payments during the month it provides services and recognizes premium revenue during the period in which it is obligated to provide services to its members.
Some states enact premium taxes or similar assessments, collectively premium taxes, and these taxes are recorded as General and Administrative expenses.
Some contracts allow for additional premium related to certain supplemental services provided such as maternity deliveries.
Revenues are recorded based on membership and eligibility data provided by the states, which may be adjusted by the states for updates to this data.
These adjustments have been immaterial in relation to total revenue recorded and are reflected in the period known.
The Company’s Specialty Services segment generates revenues under contracts with state programs, healthcare organizations and other commercial organizations, as well as from our own subsidiaries on market-based terms.
Revenues are recognized when the related services are provided or as ratably earned over the covered period of service.
Premium and services revenues collected in advance are recorded as unearned revenue.
For performance-based contracts the Company does not recognize revenue subject to refund until data is sufficient to measure performance.
Premiums and service revenues due to the Company are recorded as premium and related receivables and are recorded net of an allowance based on historical trends and management’s judgment on the collectibility of these accounts.
As the Company generally receives payments during the month in which services are provided, the allowance is typically not significant in comparison to total revenues and does not have a material impact on the presentation of the financial condition or results of operations.
Activity in the allowance for uncollectible accounts for the years ended December 31 is summarized below:
## Table 0 ##
Significant Customers Centene receives the majority of its revenues under contracts or subcontracts with state Medicaid managed care programs.
The contracts, which expire on various dates between June 30, 2007 and December 31, 2011, are expected to be renewed.
Contracts with the states of Georgia, Indiana, Kansas, Texas and Wisconsin each accounted for 15%, 15%, 10%, 17% and 16%, respectively, of the Company’s revenues for the year ended December 31, 2006.
Reinsurance Centene has purchased reinsurance from third parties to cover eligible healthcare services.
The current reinsurance program covers 90% of inpatient healthcare expenses in excess of annual deductibles of $300 to $500 per member, up to an annual maximum of $2,000.
Centene’s Medicaid Managed Care subsidiaries are responsible for inpatient charges in excess of an average daily per diem.
In addition, Bridgeway participates in a risk-sharing program as part of its contract with the State of Arizona for the reimbursement of certain contract service costs beyond a monetary threshold.
Reinsurance recoveries were $3,674, $4,014, and $3,730, in 2006, 2005, and 2004, respectively.
Reinsurance expenses were approximately $4,842, $4,105, and $6,724 in 2006, 2005, and 2004, respectively.
Reinsurance recoveries, net of expenses, are included in medical costs.
Other Income (Expense) Other income (expense) consists principally of investment income and interest expense.
Investment income is derived from the Company’s cash, cash equivalents, restricted deposits and investments.
The following table outlines the rollforward of the fair value measurement Company’s Level 3 plan assets using significant unobservable inputs for the year ended December 31, 2009 (in millions):
## Table 1 ##
11.
Accumulated Other Comprehensive Income (Loss) The components of accumulated other comprehensive income (loss) are as follows (in millions):
## Table 2 ##
12.
Commitments and Contingencies We are involved in various claims, regulatory agency audits and pending or threatened legal actions involving a variety of matters.
The total liability on these matters at December 31, 2009 cannot be determined; however, in our opinion, any ultimate liability, to the extent not otherwise provided for, will not materially affect our financial position, cash flow or results of operations.
Our business is affected both directly and indirectly by governmental laws and regulations relating to the oilfield service industry in general, as well as by environmental and safety regulations that specifically apply to our business.
Although we have not incurred material costs in connection with our compliance with such laws, there can be no assurance that other developments, such as new environmental laws, regulations and enforcement policies hereunder may not result in additional, presently unquantifiable, costs or liabilities to us.
We have received federal grand jury subpoenas and subsequent inquiries from governmental agencies requesting records related to our compliance with export trade laws and regulations.
We have cooperated fully with agents from the Department of Justice, the Bureau of Industry and Security, the Office of Foreign Assets Control, and U. S.  Immigration and Customs Enforcement in responding to the inquiries, and we have conducted our own internal review of this matter.
At the conclusion of our internal review in the fourth quarter of 2009, we identified possible areas of concern and discussed these areas of concern with the relevant agencies.
We are currently negotiating a potential resolution with the agencies involved related to these matters.
We currently anticipate that any administrative fine or penalty agreed to as part of a resolution would be within established accruals, and would not have a material effect on our financial position or results of operations.
To the extent a resolution is not negotiated as anticipated, we cannot predict the timing or effect that any resulting government actions may have on our financial position or results of operations.
As a result of our internal review and in an effort to prevent any future compliance issues of this nature, we have reviewed and are in the process of enhancing our compliance procedures and training.
The Company leases certain facilities and equipment under operating leases that expire at various dates through 2066.
These leases generally contain renewal options and require the lessee to pay maintenance, insurance, taxes and other operating expenses in addition to the minimum annual rentals.
Rental expense related to operating leases approximated $199 million, $184 million, and $128 million in 2009, 2008 and 2007, respectively.
Future minimum lease commitments under noncancellable operating leases with initial or remaining terms of one year or more at December 31, 2009 are payable as follows (in millions):
throughout North America, the segment supports major offshore drilling contractors through locations in Mexico, the Middle East, Europe, Southeast Asia and South America.
Distribution Services employs advanced information technologies to provide complete procurement, inventory management and logistics services to its customers around the globe.
Demand for the segment’s services is determined primarily by the level of drilling, servicing, and oil and gas production activities.
The following table sets forth the contribution to our total revenues of our three operating segments (in millions):

<table><tr><td></td><td>2006</td><td>2005</td><td>2004</td></tr><tr><td>Allowances, beginning of year</td><td>$343</td><td>$462</td><td>$607</td></tr><tr><td>Amounts charged to expense</td><td>512</td><td>80</td><td>407</td></tr><tr><td>Write-offs of uncollectible receivables</td><td>-700</td><td>-199</td><td>-552</td></tr><tr><td>Allowances, end of year</td><td>$155</td><td>$343</td><td>$462</td></tr></table>
<table><tr><td></td><td> Level 3  Plan  Assets</td></tr><tr><td>Beginning balance as of January 1, 2009</td><td>$24</td></tr><tr><td>Actual return on plan assets still held at reporting date</td><td>2</td></tr><tr><td>Purchases, sales and settlements</td><td>1</td></tr><tr><td>Currency impact</td><td>5</td></tr><tr><td>Ending balance as of December 31, 2009</td><td>$32</td></tr></table>
<table><tr><td></td><td>Change in Defined Benefit Plans</td><td>Cumulative Currency Translation Adjustment</td><td>Derivative Financial Instruments</td><td>Total</td></tr><tr><td>Balance at December 31, 2006</td><td>$-15</td><td>$60</td><td>$1</td><td>$46</td></tr><tr><td>Current period activity</td><td>-8</td><td>211</td><td>25</td><td>228</td></tr><tr><td>Tax effect</td><td>3</td><td>-75</td><td>-7</td><td>-79</td></tr><tr><td>Balance at December 31, 2007</td><td>$-20</td><td>$196</td><td>$19</td><td>$195</td></tr><tr><td>Current period activity</td><td>-30</td><td>-265</td><td>-241</td><td>-536</td></tr><tr><td>Tax effect</td><td>10</td><td>89</td><td>81</td><td>180</td></tr><tr><td>Balance at December 31, 2008</td><td>$-40</td><td>$20</td><td>$-141</td><td>$-161</td></tr><tr><td>Current period activity</td><td>-14</td><td>150</td><td>223</td><td>359</td></tr><tr><td>Tax effect</td><td>5</td><td>-50</td><td>-63</td><td>-108</td></tr><tr><td>Balance at December 31, 2009</td><td>$-49</td><td>$120</td><td>$19</td><td>$90</td></tr></table>

Question: What is the growing rate of Tax effect in the years with the least Current period activity?