The US National Income and Product Accounts show that the effective rate of corporate profits tax (the percentage of profits actually paid to the government in taxes) crested at 33.7% in the first quarter of 2000 - the peak of the stock market and the economy in general - and fell to 20.2% in the fourth quarter of 2003, when the market was down. Much of that decline reflects explicit tax relief measures voted by Congress, as well as the perception among corporations that in the current economic and political environment they can be more aggressive in tax avoidance.