IOWA CITY, Iowa (AP) — Democratic presidential candidate Cory Booker released 10 years of tax returns Wednesday, showing his income plunged last year but he remained generous toward charity.

Booker reported income of $152,715 in 2018 for his salary as a U.S. senator from New Jersey. He paid $22,781 in taxes and had an effective tax rate of 19 percent.

Booker donated $24,000 to charity in 2018 — or more than 15 percent of his income. That contrasts with other Democratic presidential candidates who have reported giving much smaller percentages to charity in their tax returns, often 2 percent or less.

Booker, who is single and has no children, reported total charitable contributions of nearly $460,000 over the 10-year period. Slightly more than half of those donations came in 2013, when Booker faced criticism over his role founding the social media company Waywire and gave significant amounts of stock to Newark charities.

Booker wasn't required to list all the charities to which he gave, but the Monmouth Medical Center Foundation, Metropolitan Baptist Church and the AIDS Resource Foundation for Children were among the 2013 recipients.

Booker reported a higher income in 2015, 2016 and 2017 from advances and royalties off the sale of his book, "United," which was released in 2016. Booker reported income of $429,983 in 2017 and $466,168 in 2016.

Before he was elected to the Senate in 2013, Booker also made significant income from paid public speaking engagements while serving as mayor of Newark. His tax returns show he made more than $1.7 million in speaking fees from 2009 through 2013. Groups such as universities, nonprofits and companies paid him up to $30,000 per speech.

Booker is the latest among several Democrats vying for the party's 2020 presidential nomination to release years of past tax information. Sen. Bernie Sanders, Sen. Elizabeth Warren, Sen. Amy Klobuchar, Sen. Kirsten Gillibrand, Sen. Kamala Harris, former U.S. Rep. Beto O'Rourke and Washington Gov. Jay Inslee have done so.

That's in contrast to President Donald Trump, who has bucked longtime presidential tradition and declined to make his tax filings public.

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