Bill and Hillary Clinton saw a sizeable dip in their adjusted gross income in 2015 after she stopped giving paid speeches and started running for president, according to a batch of tax documents released Friday.

The financial documents released Friday by the Democratic presidential candidate show the Clintons paid an effective federal tax rate of 34.2 percent in 2015. The same tax returns also showed their adjusted gross income last year was $10.6 million.

Though impressive, this figure is actually miniscule compared to their numbers from 2014, when Hillary Clinton alone earned $10.5 million in speaking fees, combining with Bill Clinton for an overall impressive adjusted gross income of nearly $28 million.

There's a reason for the drop of more than $17.4 million between 2014 and 2015: Hillary Clinton stopped giving paid speeches after she announced her candidacy in April of last year.

But that's not to say that the Clintons didn't earn a fair chunk of change in 2015 from giving paid speeches.

Together, the former president of the United States and the former secretary of state still took in a combined $6.72 million last year from giving paid speeches.

Bill Clinton drew in $5.25 million from speaking engagements in 2015, and Hillary Clinton took in $1.47 million.

Now compare that to 2014, when Bill Clinton took in $9.7 million in speaking fees, and Hillary Clinton earned a whopping $10.5 million from doing the same. Or compare it to 2013, when she earned $9.6 million from speaking to various groups.

Hillary Clinton's lucrative speaking gig came under close scrutiny during the Democratic presidential primary after her chief rival, Sen. Bernie Sanders, I-Vt., called on her repeatedly to release the text of her paid remarks to various Wall Street giants, including Goldman Sachs and Bank of America.

Clinton refused then, and she refuses now to release the text of her Wall Street speeches.

But when it comes to taxes, the Clintons are a bit more open: The have made public their tax information dating back as far as 1977. Democratic vice-presidential nominee Sen. Tim Kaine, D-Va., also released 10 years' worth of tax returns on Friday.

Clinton's campaign is now calling on GOP nominee Donald Trump to follow their lead and release his tax returns.

"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 statement Friday.

"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?" she asked.

Trump has refused all throughout the 2016 election cycle to release his tax information, and he has avoided doing so by issuing a number of excuses, including that he is under audit and that there is "nothing to learn from them."

Trump's refusal to release his tax returns has drawn criticism not just from Democrats, but also from conservatives, including Sen. Ted Cruz, R-Texas, former Massachusetts Gov. Mitt Romney and political analyst George Will, who've suggested the GOP nominee has something to hide.

"Either he is not anywhere near as wealthy as he says he is or he hasn't been paying the kind of taxes we would expect him to pay," Romney said in an interview on Fox News in February. "Or perhaps he hasn't been giving money to the vets or the disabled like he has been telling us he has been doing."