Approximately 22.7 million individual income tax returns reported non-farm sole proprietorship profits of $244.8 billion for tax year 2009 according to the recently released Statistics of Income Quarterly Report.  Check it out here -> Summer 2011

Some other points worth noting in my opinion include:

1. For tax year 2008, almost 67,000 foreign-controlled domestic corporations reported combined profits of $21.8 billion.

2. 6,675 corporations claimed a total foreign tax credit of $86.5 billion against their U.S. income tax liability in tax year 2007.

3. Nearly 37,000 estate tax returns were filed for decedents who died in 2007 with total gross estates of $2 million or more, the filing threshold for that year reporting a combined total of $224.8 billion in assets.