WASHINGTON (AP) — Donald Trump doubled his campaign expenses last month yet was still spending at a far slower clip than Hillary Clinton.

New finance documents show the Republican presidential nominee’s campaign spent about $18.5 million in July. By comparison, the Democratic presidential nominee spent about $38 million.

Trump has continued to increase the size of his operation, putting $5 million this month into his first batch of TV ads. Clinton has been running general election ads for months.

The New York businessman gave his campaign another $2 million in July. He’d pledged to contribute as part of a fundraising pitch to small donors, telling them he’d match their efforts up to that amount.

In all, his campaign brought in $37 million. Clinton’s campaign raised $52 million.