I got the numbers from the IRS statistics site. The latest figures there were for 2008.
There were 142M total tax filers in 2008. The total effective tax rate for all payers was 13.9%.
87% of tax filers had AGI of under $100,000 and paid an effective tax rate below 10%.
Here is at table showing the number of tax filers in each income group and their respective effective tax rates:
# filers | % of AGI | |
No adjusted gross income | 2,489,989 | 0.0% |
$1 under $5,000 | 11,638,707 | 5.0% |
$5,000 under $10,000 | 12,139,638 | 2.6% |
$10,000 under $15,000 | 11,702,056 | 2.9% |
$15,000 under $20,000 | 11,076,002 | 3.8% |
$20,000 under $25,000 | 9,866,247 | 5.2% |
$25,000 under $30,000 | 8,743,581 | 6.2% |
$30,000 under $40,000 | 14,554,280 | 6.8% |
$40,000 under $50,000 | 11,087,123 | 7.5% |
$50,000 under $75,000 | 19,196,461 | 8.5% |
$75,000 under $100,000 | 11,729,485 | 9.3% |
$100,000 under $200,000 | 13,851,341 | 12.7% |
$200,000 under $500,000 | 3,476,747 | 19.6% |
$500,000 under $1,000,000 | 577,618 | 24.1% |
$1,000,000 under $1,500,000 | 140,635 | 24.8% |
$1,500,000 under $2,000,000 | 59,460 | 25.0% |
$2,000,000 under $5,000,000 | 86,329 | 24.8% |
$5,000,000 under $10,000,000 | 21,390 | 24.0% |
$10,000,000 or more | 13,480 | 21.1% |
Here is the data shown graphically :
For the picture I chopped off the data at the $1M income level just to make the picture cleaner.