Ayende tax problem

damnTaxes.cs

public class TaxBracket
    {
        public decimal Minimum { get; set; }
        public decimal Percent { get; set; }

        public TaxBracket(decimal taxWindow, decimal percent)
        {
            Minimum = taxWindow;
            Percent = percent;
        }

    }

    class Taxing
    {
        private readonly IEnumerable<TaxBracket> _taxRates = new[]
		                                                          {
                                                                        new TaxBracket(40230m, .45m),                                                                            		                                                                 	
		                                                                new TaxBracket(21240m, .33m),
                                                                        new TaxBracket(14070m, .30m),
                                                                        new TaxBracket(8660m, .23m),
                                                                        new TaxBracket(5070m, .14m),
                                                                        new TaxBracket(0,.1m),
		                                                            };
        public decimal GetTaxAmount(decimal salary)
        {
            var taxSum = 0m;

            foreach (var taxBracket in _taxRates.SkipWhile(x => salary < x.Minimum))
            {
                var taxedPart = salary - taxBracket.Minimum;
                taxSum += taxedPart * taxBracket.Percent;
                salary = salary - taxedPart;
            }

            return taxSum;
        }
    }