Democratic presidential candidate Joe Biden and his wife, Jill, wave to the crowd during his 2020 campaign kickoff rally at the Eakins Oval in Philadelphia, Pa., on Saturday, May 18, 2019.

Joe Biden and his wife Jill earned more than $15 million in the two years after the former vice president left the Obama administration, according to tax returns released by his presidential campaign Tuesday.

The couple reported about $11 million in adjusted gross income in 2017, the documents from 2016 through 2018 show. They followed it up with another $4.6 million in adjusted gross income last year. Their income spiked from about $396,000 in 2016.

The Bidens paid about $3.7 million and $1.5 in taxes for 2017 and 2018, respectively — about a third of their adjusted gross income. They gave roughly $1 million and $275,000 to charity in 2017 and 2018, respectively.

Biden easily raked in the most money in the past two years among 2020 Democratic presidential candidates who have released tax returns so far. After the former vice president left the White House in January 2017, the Bidens pulled in millions from Joe Biden's speaking engagements and books written by both Joe and Jill Biden.

The money Biden accumulated after his decadeslong career as an elected official clash with the image he has tried to craft as a humble champion of the working and middle class. The former senator from Delaware has referred to himself as "Middle-Class Joe" and touted his efforts to lift up union workers and low-income families.