Washington (CNN) Sen. Kamala Harris raised a solid $12 million for her presidential campaign during the first fundraising quarter of the 2020 campaign season, her aides announced Monday night.

The California Democrat's haul, disclosed the day after the close of the fundraising period, exceeds the $7 million announced earlier Monday by South Bend, Indiana, Mayor Pete Buttigieg. They are the only 2020 contenders to reveal topline figures for the three-month period so far.

Details on candidates' fundraising and spending are not due to federal election regulators until April 15, but candidates often provide totals as they jockey to demonstrate the financial strength of their campaigns.

In a news release, Harris said she had received 218,000 individual contributions during the first quarter and 98% percent of those contributions came in amounts smaller than $100. Small-dollar donors could prove crucial in a crowded Democratic primary because they can be tapped repeatedly for contributions before hitting the $2,800 limit on what an individual can donate to a candidate for the primary election.

Harris' aides say that more than 99% of her current donors can contribute again without hitting the limit.

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