Gov. Mark Dayton acknowledged Wednesday that he was embarrassed by the tax return he released Tuesday that showed he had given only $1,000 to charity despite total earnings of $343,234 last year, according to his tax returns released this week.

"I pride myself on my charitable giving and I'm disappointed in myself." Dayton said at the end of a briefing with reporters on another issue. "I totaled it up and noticed I had fallen off, so I will remedy that."

The drop was significant from 2009, when Dayton, then a gubernatorial candidate, earned $172,475 mostly from family trusts, and donated nearly $27,000 of that to charity.

In addition to his $116,125 state salary in 2012, Dayton received $92,381 from a family trust and $130,291 from capital gains.

Dayton gave $1,750 to charity in 2011, when his earnings totaled $342,322.

Dave Thompson, the only Republican candidate running against Dayton to release his tax return, declared joint income with his wife of $198,322. His family gave $20,465 to charity.

Dayton's mea culpa came on the eve of Give to the Max Day in Minnesota, a 24-hour fundraiser for schools and nonprofits by that features matching grants.