GENEVA (AP) — The U.N.'s migration agency has tallied a 17-percent increase this year in deaths among migrants trying to cross from Mexico to the United States compared to a year ago.

The International Organization of Migration counts 232 migrant deaths on the route through the end of July, up from 204 a year earlier. It comes even though U.S. Border Patrol apprehensions of migrants have fallen nearly by half this year, to just over 140,000.

IOM said Friday that 50 bodies were found in July alone, including 10 discovered in a truck in San Antonio, Texas.

The Geneva-based agency said the higher toll couldn't be fully explained. It made no reference to President Donald Trump's calls for tighter border controls, but cited factors like hot weather and swelling Rio Grande waters.