36.5% of the US Gross Domestic Product.
Now, in 2000, the US GDP was about $10 trillion, and I know it's more now. But using the $10 trillion figure for a moment, that would mean that in 2006 the US government confiscated $3.65 trillion dollars from the pockets of taxpayers.
* * *
...yes, that's all I've got today. Sorry.