Hillary Clinton,Tim Kaine

In this July 29, 2016, photo, Democratic presidential candidate Hillary Clinton and Democratic vice presidential candidate, Sen. Tim Kaine, D-Va., look to the audience as they finish speaking during a rally at McGonigle Hall at Temple University in Philadelphia. Clinton doesn't appear all that interested in making any scenic stops on her state-to-state quest to become president.

(Andrew Harnik, AP Photo)

CLEVELAND, Ohio -- Democratic presidential candidate Hillary Clinton on Friday released her 2015 tax return, adding to a large stack of tax documents she's already made public.

Clinton has shared tax returns for every year going back to 1977. And on Friday, her vice presidential pick, Tim Kaine, followed suit, and released his tax returns for the last decade.

The Clinton campaign attacked her Republican opponent, Donald Trump, for failing to make his own tax documents public. Trump said in May that he will release his tax returns once a routine audit is complete, according to CNN.

"Hillary Clinton and Tim Kaine continue to set the standard for financial transparency as she releases her 2015 personal tax return and builds on the Clintons' tradition of making their returns public since 1977 and Kaine releases 10 years of his returns," Hillary for America communications director Jennifer Palmieri said in a news release. "In stark contrast, Donald Trump is hiding behind fake excuses and backtracking on his previous promises to release his tax returns. He has failed to provide the public with the most basic financial information disclosed by every major candidate in the last 40 years. What is he trying to hide?"

The newly released tax documents show that the Clintons in 2015 paid a combined federal, state and local effective tax rate of 43.2 percent. They gave 9.8 percent of their adjusted gross income to charity.

The Kaines between 2006 and 2015 paid a combined federal, state and local effective tax rate between 18.7 percent and 29.1 percent.

In those years, they gave 7.5 percent of their adjusted gross income to charity.

The Clinton campaign also released a video criticizing Trump for failing to release his tax returns.