Florida Sen. Marco Rubio released summaries of his tax filings from the last five years Saturday, showing that he has received a regular senator’s income of $176,000 as well as extra funds from several book deals. 

During his time as a senator, Rubio and his wife, Jeanette, earned a combined average of $531,000 per year, the returns show. Since Rubio was elected to the Senate in 2010, the couple's income has ranged from $276,059 to $938,693.

Most of the income came from a company that collected royalties on two books, the Associated Press reported. The documents released are not complete tax filings, but are the first two pages of his 1040 forms, which provide a summary of his income and taxes.

The documents show that Rubio has paid between $46,500 and $245,894 in federal income tax since winning election to the Senate. When former presidential candidate Mitt Romney and Hillary Clinton released their tax returns, they both released the full tax filings.

Rubio’s release of these documents comes after a heated exchange on the topic with Republican front-runner Donald Trump during Thursday’s GOP debate. Trump said that his tax returns have been audited for many years and asserted that he could not release his returns until that process comes to an end.

“You don't learn anything from a tax return,” Trump said during the debate. “As far as my return, I want to file it except for many years, I've been audited every year. Twelve years or something like that. Every year they audit me, audit me, audit me. I have friends that are very wealthy people” who never go through that process, he added.

During the debate, Rubio promised to release his own tax returns on Saturday. Rubio’s campaign said Saturday that they hoped by releasing their candidate’s information, they would encourage Trump and others to follow suit.

“We're putting these out today to put pressure on Trump and the other candidates to release theirs,” Rubio campaign spokesman Alex Conant told the AP. “To the extent there are additional questions about Marco, we won't rule out providing more information in the future.”

Rubio is the only one of the top three Republican candidates to release tax information so far. Texas Sen. Ted Cruz also criticized Trump during the debate, but he had yet to release his tax documents on Saturday. A Cruz spokesperson told the AP that they are still planning to release the returns.

The returns from Rubio add to 10 years of earlier tax returns he published when running for the Senate. Rubio and Cruz both attacked Trump during Thursday's debate, and have continued to lash out at the front-runner,  hoping to stop his progress as they head into Super Tuesday next week.