Black inmates in the Travis County Jail were locked up for longer periods of time in 2015 than white inmates charged with same-level offenses, according to a new study from the nonprofit Grassroots Leadership.

The report found black inmates spent an average of 22 days per booking in the jail compared to 16 days for Hispanic inmates and 13 days for white inmates.

“Unfortunately, the data also clearly reflects that law enforcement, pre-trial services and magistrates in Travis County genuinely believe it’s acceptable for people with more melanin than others to be detained at higher rates than their Eurocentric counterparts,” said Fatima Mann, executive director of Counter Balance ATX, a group that works to empower marginalized people.

The report breaks down the data by specific charge, charge count and level of offense. Driving while intoxicated was the most common charge for which someone was booked in 2015.

According to the report, on average black inmates charged with driving while intoxicated spent an average of 14 days in jail, compared to 13 for Hispanic inmates with the same charge and five days for white inmates.

Travis County Judge Sarah Eckhardt said the numbers troubled her, but they didn't surprise her.

"We've been doing some really good investment and really good work in trying to untie this shameful knot of institutional racism in the justice system," she said. "We have made some strides, but there's clearly a lot more work to do."

She said the county needed to take a hard look at the data.

"These are painful truths but we need to get behind the numbers and find out why this is the case," she said.

Correction: A previous version of this post incorrectly stated black inmates charged with driving while intoxicated were charged with five counts of the offense.