WASHINGTON (CNN) -- Sen. John McCain is considered one of the wealthiest members of Congress, but you wouldn't know it by looking at tax returns released Friday by his presidential campaign.
Sen. John McCain and his wife, Cindy, file their taxes separately.
Out of 535 members of Congress, Roll Call newspaper last year ranked McCain the ninth richest.
In 2007, McCain's total income was $405,409; his taxable income was $258,800; he paid $188,660 in taxes.
The campaign did not release tax returns for McCain's wife, Cindy, heiress to a fortune from her father's beer distribution company, Hensley and Company, for which she now serves as chairman.
According to last year's Senate financial disclosure form, the McCains have assets of at least $36.5 million. Some estimates put her worth at $100 million.
Before marrying 27 years ago, the McCains signed a prenuptial agreement to keep their finances separate and they file their taxes separately. Watch more on the candidates' taxes »
McCain's campaign said Cindy is not releasing her returns "in the interest of protecting the privacy of her children."
Michelle Obama, who has young children, did release her tax records, filed jointly with her husband, Sen. Barack Obama.
Sen. Hillary Clinton and former President Bill Clinton file taxes jointly.
"My life has not been one of privilege and luxury. I had the great honor of serving in this country," McCain has said.
The 71-year-old presumed GOP nominee received about $23,000 last year in Social Security, and paid nearly $18,000 in alimony to his ex-wife. He received more than $58,000 from his Navy pension.
He earned nearly $177,000 in book royalties, which he and his wife donated to charity -- and McCain donated an additional $17,000.
McCain donated about 26 percent of his income to charity. By comparison, the Clintons gave 15 percent, and the Obamas gave 6 percent.
Almost all of McCain's donations went to the John and Cindy McCain Family Foundation. The foundation supports charitable ventures such as clearing land mines and aid for children with cleft palates, which the McCains' adopted daughter had.
The Democratic National Committee released a statement Friday calling the McCains' lack of transparency troubling and said not releasing Cindy McCain's taxes "raises questions about what he is hiding."
McCain campaign advisers defended not releasing his wife's tax returns by comparing the situation to Democratic Sen. John Kerry's campaign four years ago. Kerry's multimillionaire wife refused to disclose all of her tax returns, which Republicans criticized. E-mail to a friend