Some 125 U.S. prisoners were exonerated for crimes they didn’t commit last year, marking the most in the 25 years since the U.S. first began recording them 1989, the National Registry of Exonerations said Monday. The record number in 2014 was the first time the total has notched above 100 in a single year. The number of exonerations in 2013 was 91. Samuel Gross, a professor at the University of Michigan law school who wrote the registry’s annual account, pointed to the spread of “conviction integrity units” dedicated to exonerating innocent prisoners. The U.S. now has 15 such units, with six created last year alone, but Gross added that the majority of the country still lacks a program like a conviction integrity unit. The report also highlighted that almost four in 10 of last year’s exonerated prisoners pleaded guilty to crimes they did not commit.