Attorney General Eric Holder backed a proposal that would reduce prison sentences for nonviolent drug traffickers by about a year.

A US Sentencing Commission plan would reduce federal guidelines for sentencing drug dealers from sixty-two months to fifty-one months. Holder announced his support for that plan before the commission Thursday.

The plan would affect nearly 70 percent of drug trafficking offenders and trim the federal prisoner population by 6,550 inmates within five years, according to a Department of Justice analysis. Nearly half of the 216,000 federal inmates currently serving time in US prisons are incarcerated for drug-related offenses.

“As it stands—and as this Commission has recognized—certain types of cases result in too many Americans going to prison for too long, and at times for no truly good public safety reason,” Holder said. “Although the United States comprises just five percent of the world’s population, we incarcerate almost a quarter of the world’s prisoners.”

Holder focused on the financial benefits of reducing prison sentences, noting that state and federal governments spent about $80 billion a year on incarceration in 2010. He also cited a study suggesting that seventeen states diverting funds away from prisons to evidence-based diversion programs will save $4.6 billion over ten years.

Holder acknowledged that the proposal is “measured in scope.” Even if the seven-member commission approves the plan in April, as is expected, the United States will likely maintain the world’s largest prison population by a significant margin.

The announcement comes as Holder and members of Congress push a proposal to end mandatory minimums for nonviolent drug offenders and to grant clemency for crack offenders serving disproportionate sentences.