It's no secret that Hillary and Bill Clinton have made a ton of money by speaking to crowds during public appearances. Go ahead and add former president George W. Bush to the list of politicians that earn six figures a speech on the talk circuit.

Since 2009, Bush has made at the very least 200 speeches and walked away from each of them with between $100,000 and $175,000 in his pocket, according to Politico. Overall, Bush has earned "tens of millions of dollars" through lectures, the website reported.

Bush never kept his plans a secret, as he openly talked about making a living off of speeches while he was in office. He told Robert Draper, who was reporting for his book "Dead Curtain," that lecturing would allow him to make "ridiculous" amount of money in order to "replenish the ol' coffers."

"I don't know what my dad gets, but it's more than 50, 75 (thousand dollars a speech), he said. "Clinton's making a lot of money."

Bill Clinton was asked about the lucrative business of public speaking last month and said "I gotta pay the bills."

The difference between what the Clintons do and what Bush does is mainly the audiences they talk to. Bush sticks to more private events. According to Politico, he has spoke at a wide range of people, from events at the National Grocers Association, the National Association for Home Care and Hospice, the National Association of Chain Drug Stores, the Work Truck Show and even the Bowling Proprietors' Association of America.

With the private events come more strict contractual obligations.

"I signed a confidentiality agreement," Frances Atchison, the co-chair of the Distinguished Lecturer Series in Vero Beach, Fla. told Politico. 

Added Carol Walden, a spokesperson for FARE, a conference about the food business Bush has worked with, "We're precluded by contract from sharing any of the particulars."

Politico reached out to a Bush spokesperson for clarification on an exact figure he has earned for public speeches, but could not get a straight answer because that kind of information is not kept.

"I don't have such a record of his speeches," Bush spokesman Freddy Ford said.