Black men in the U.S. are more likely to be sent to prison than white men, and often on drug offenses. A University of Wisconsin-Milwaukee study found that Wisconsin’s incarceration rate for black men — 13 percent — was nearly double the national rate, NPR reports. “We were so far above everybody else. That just sort of stunned us when we saw that,” says Prof. John Pawasarat. He found that nearly 1 in 8 black men of working age in Milwaukee County had served time in the state. At 13 percent, the rate was about 3 percentage points above Oklahoma’s — the state with the second highest rate of incarceration for black males. “The explosion really took place in the year 2000 to 2008 where mandatory sentencing, three strikes was put in place and it more than tripled the population in just a few years, which meant about half of the black men in their 30s or early 40s in Milwaukee County would have spent time in the state’s correctional facilities. And two-thirds of the men come from the six poorest zip codes in Milwaukee,” says Pawasarat.