The number of people convicted of a drug offense carrying a mandatory minimum sentence fell last year, according to a new report by the U.S. Sentencing Commission.

In fiscal year 2015, 45.8 percent of drug offenders were convicted of an offense carrying a mandatory minimum penalty, compared with more than 50 percent the previous year, the Associated Press reports.

The findings suggest federal prosecutors are continuing to follow guidance issued in 2013 by then-Attorney General Eric Holder, who told Justice Department attorneys to limit their use of mandatory minimum sentences.

The Washington Post reports that President Obama is expected to grant clemency to another group of drug offenders in the coming weeks. In December he commuted the sentences of 95 drug offenders, more than double the number he granted last summer.

The White House will hold an event on March 31 called “Life After Clemency,” which will include former inmates and their attorneys, as well as prison reform advocates.

Some prosecutors and law enforcement officials oppose changes to mandatory minimum sentences for some drug charges. They say the changes will make it more difficult for them to go after criminal organizations or uncover other crimes.

Proponents of changing mandatory minimum sentences for drug charges say judges should have more flexibility in matching prison sentences to the threat defendants pose to public safety. Defense attorneys say the threat of having to serve a decades-long sentence leaves defendants without a choice at the plea bargaining table.

Advocates for changing the current drug sentencing laws say mandatory minimum sentences have been used to lock up low-level nonviolent offenders who face punishments that are much harsher than their crimes. They note the policies have disproportionately affected minority communities.