Bernie Sanders released his full 2014 federal tax return Friday, revealing that he mostly lives off a six-figure government salary and donated about 4 percent of his family's income to charitable causes.

Sanders and his wife, Jane, donated $8,350 to charity while reporting an adjusted gross income of about $205,000 that year, according to his tax return. The share of his family's income that went to charity was about half the percentage of income that his primary opponent, former Secretary of State Hillary Clinton, and her husband, former President Bill Clinton, gave to charitable groups.

The Sanders campaign released the return a day after a heated Democratic presidential debate in New York in which Sanders pledged to release the single return but hesitated to say when he would release additional years of his taxes.

Sanders campaign didn't immediately respond Friday evening to emailed questions seeking additional details about Sanders' charitable giving.

Since 1976, every major party presidential nominee has released full tax returns. So far this year, though, Clinton is the only major-party presidential candidate who has released several years of full tax returns. GOP front-runner Donald Trump hasn't released any of his returns, and Texas Sen. Ted Cruz and Ohio Gov. John Kasich have only released partial returns.

Until Friday, Sanders had only released an excerpt from his 2014 tax return. During Thursday's debate, Clinton attacked Sanders for failing to release more.

"I've released 30 years of tax returns, and I think every candidate, including Senator Sanders and Donald Trump, should do the same," said Clinton, the Democratic front-runner.

Sanders fired back at Clinton, contrasting his modest wealth with Clinton's multimillion-dollar income, a significant portion of which has come in the form of paid speeches to corporate and interest groups.

"I don't want to get anybody very excited. They are very boring tax returns," Sanders said. "No big money from speeches, no major investments. Unfortunately, I remain one of the poorer members of the United States Senate. And that's what that will show."

In 2014, the Clintons donated more than $3 million— nearly 11 percent of their income. Since 2000, the Clintons have given nearly $15 million to charity, tax returns show.