Income Taxes

The effective income tax provision rate was 38.0% for the six months ended June 30, 2011, compared with a benefit rate of 42.3% for the six months ended June 30, 2010. In determining the quarterly provision (benefit) for income taxes, the Company used an estimated annual effective tax rate, which was based on expected annual income, statutory tax rates, and its best estimate of non-deductible and non-taxable items of income and expense. Income tax expense (benefit) varies from the amount computed by applying the federal corporate income tax rate of 35.0% to income before income taxes primarily due to state income taxes, net of federal income tax effect, Canadian income taxes, and adjustments for permanent differences.