WASHINGTON (Reuters) - President Barack Obama and his wife Michelle donated less to charities in 2015 as their income also dipped, tax returns released by the White House showed on Friday. The Obamas donated $64,066 to 34 charities last year, down nearly 9.4 percent from their donations of $70,712 in 2014 to 33 charities.  For both years, the couple donated slightly less than 15 percent of their income to charity. On average, Americans donate about 3 percent of their income to charity, according to the Chronicle of Philanthropy. The Obamas earned $436,065 in 2015, down nearly 8.7 percent from $477,383 in 2014, continuing a downward trend as sales of the president’s books slowed. As president, Obama is entitled to a $400,000 annual salary. Most of the rest of the couple’s income came from the book sales.  Their top charity donation of $9,066 went to Fisher House Foundation, which provides housing for military families near military hospitals. The couple gave the organization $22,012 in 2014.  The couple also gave $5,000 to the Beau Biden Foundation, an organization that honors the life of Vice President Joe Biden’s son, who died of brain cancer last year.  The Obamas paid $81,472 in total tax, with an effective federal income tax rate of 18.7 percent. Biden and his wife Jill, a community college professor,  reported a combined income of $392,233, up from $388,844 in 2014.   
Obamas donated less to charities in 2015 as income slipped