Five years of traffic-stop data collected by Vermont State Police show a black motorist who is pulled over is nearly five times more likely to be searched than a white driver, while contraband is more likely to be found when a white driver is searched.

The data were collected by state troopers on traffic details between July 2010 and December 2015 and analyzed by the Institute on Race and Justice at Boston's Northeastern University. The findings were presented Tuesday evening in a meeting of the State Police senior command staff and an anti-bias committee of police employees and residents.

A presentation at the meeting did not include raw numbers of African-Americans or members of other minority groups searched, but provided the total number of stops and the percentages by race and ethnicity. The percentage of stops of whites that resulted in searches was 1.1; the percentage involving black drivers was 5.1.

Contraband was found in searches of whites 80 percent of the time; for blacks the percentage was 68.5 percent of the time.

State Police director Col. Matthew Birmingham, said the cause of the disparity appeared to be unintentional on the part of troopers making the stops.

"Implicit human bias is a very complicated thing to understand, and changing human behavior is a complicated thing to understand," Birmingham said.

Part of police training is "just to acknowledge we all have it," Birmingham said. That would be a first step toward "moving these numbers in a positive direction."

Some in the audience Tuesday complained that the search data did not specify when the search results were minor, as in a small amount of marijuana in the car.

The data collection began amid a nationwide concern about racial profiling by police. The race or ethnicity of drivers was recorded in 278,129 of 282,938 traffic stops, leaving a gap of 4,809 that drew criticism from some at the meeting.

"That is a training issue. That is something we need to push down to our supervisors, to make sure we're getting complete data," said Public Safety Commissioner Keith Flynn.

Several residents who attended the meeting took issue with remarks made by the institute's director, Jack McDevitt, about drug investigations targeting gangs made up of specific minority groups.

"From a community perspective, where I stand, you look like you're on their side to me, OK? And this looks like this is not legitimate," said Mark Hughes, co-founder of the Montpelier-based advocacy group Justice For All.

Hughes also sought assurances there would be good follow-up by police working to correct biases.

Birmingham said the traffic-stop data would be compiled and analyzed annually, in part as "an early-warning system" for any problems cropping up.