The number of arrests along the Southwest border have climbed back up to Obama-era levels in the first two months of the new fiscal year, suggesting President Donald Trump’s effect on illegal immigration has worn off after early progress.

Just under 40,000 people were either arrested trying to illegally cross the border or were turned away at ports of entry in November, about 12 percent more than in October, according to Customs and Border Protection (CBP) data released Friday.

The combined total of arrests and inadmissible migrants in November was lower than the same month of the last two fiscal years, but exceeded the totals in FY2013, 2014 and 2015.

Border arrests are used as a proxy for overall levels of illegal immigration. The idea is that, assuming a given standard of border security, more apprehensions mean that more illegal aliens are slipping undetected into the U.S., and vice versa.