Nearly 400,000 supporters have given money to Democratic presidential contender Hillary Rodham Clinton's campaign so far, up from 250,000 who had made contributions by the end of June, her campaign said Thursday.

The nearly 150,000 new contributors who came aboard in the last three months show that Clinton was able to expand her donor base during a rocky period for her campaign, when she was buffeted with questions about her use of a private e-mail server as secretary of state.

Clinton still has fewer donors than Sen. Bernie Sanders of Vermont, who has created a massive low-dollar finance operation powered by 650,000 supporters. He has already collected more than 1.3 million donations, surpassing Barack Obama's contribution rate in his two campaigns.

Clinton has received 600,000 contributions from nearly 400,000 individuals so far this year, her campaign said Thursday as it filed its third-quarter fundraising report. More than 60 percent of her donors are women.

She reported raising $29.5 million in the last three months, including $691,000 in general election funds. Contributions of $200 and less made up just $5.2 million of her total, underscoring Clinton's reliance on big donors.

Sanders, by comparison, raised a staggering $20.1 million in small contributions in the third quarter -- 77 percent of his $26.2 million overall haul for the summer. His campaign said Thursday that it collected another $3.2 million since Tuesday's first Democratic debate.

Sanders spent just $11.3 million last quarter, ending September with almost $27.1 million in the bank.

Clinton spent at a much faster pace, shelling out $25.7 million as her campaign made deep investments in building its data analytics and national ground operation. Her biggest expense was for staff: $8.5 million went to payroll and taxes.

She headed into October with nearly $33 million on hand.