Donald Trump began paying nearly five times in monthly rent for his presidential campaign headquarters once he began accepting funding from donors, according to a close analysis of his Federal Election Commission filings published by the Huffington Post on Monday.

Back in March, when he said his campaign was entirely self-funded, Trump paid Trump Tower Commercial LLC $35,458 for rent. That amount was consistent with what he had paid since launching his presidential bid in the summer of 2015. By July, however, once he started raising funds from donors, he paid $169,758 in rent for the same space.

The Huffington Post noted that the discrepancy was particularly striking since Trump was paying 197 employees and consultants in March, compared to only 172 in July. The filings don’t clarify whether Trump is now renting significantly more office space in his midtown Manhattan building or why he would do so given his reduced staff size.

Trump’s campaign did not respond to HuffPo’s request for comment.

According to HuffPo’s analysis, the amount of rent paid for the Trump Tower space slowly crept up beginning in late spring. The campaign paid $72,800 in rent May 31, $110,684 on June 9, and $169,758 on July 10.

Trump’s most recent FEC reports indicate that he has also continued to funnel campaign funds back into his own businesses, including his golf courses, hotels, and restaurants.

In July, Trump’s campaign spent $18.5 million, which was significantly more than it spent in previous months, but the money went towards unusual ends. A whopping $8.4 million was paid to digital marketing company Giles-Parscale and little has been spent on building up a traditional ground game in battleground states.