President Barack Obama and First Lady Michelle Obama paid an effective tax rate of just 18.4% in 2012 federal income tax.

The figures, released by the White House, come as Obama included in his recently released budget the so-called “Buffett Rule,” which would slap a 30% minimum tax on anyone earning $1 million.

The Obamas paid $112,214 in federal taxes and $29,450 in Illinois state income tax on an adjusted gross income of $608,611–$274,000 of which came from the president’s book royalties. The Obamas’ gross adjusted income fell significantly from 2011, when it was $789,674 and even further from the $5.6 million in 2009. 

During the 2012 presidential campaign, Obama attacked Republican rival Mitt Romney for having paid an effective tax rate of 15%. Romney paid a lower tax rate because the bulk of his income was derived from investments. 

The Obamas’ tax filings also reveal that the first couple donated 24.6% to charity, a sum still under the 29.4% the Romneys donated in 2011. Vice President Joe Biden and Dr. Jill Biden increased their charitable giving last year from 1.5% in 2011 to 1.87% in 2012.