The population loss Chicago has been experiencing in recent years is well-documented, but going over the data with a fine-tooth comb reveals a surprising side effect. Chicago is now the country’s most educated big city, Crain’s Chicago Business reported, citing data from the U.S. Census Bureau.

In 2016, 38.5 percent of the city’s population 25 or older had at least a bachelor’s degree, a jump from 29.3 percent in 2006, according to the American Community Survey. Crain’s reported that that increase is higher than the country’s other four largest cities and is more than twice the national increase of 4.3 percent.

The outlet said this is because many who are leaving the city are lower-income black people without a college education fleeing violence, while there remains a steady trickle of white, Asian and black people relocating to Chicago who are more educated. The data showed that 42,000 black lesser-educated black residents left Chicago last year, but the city has gained 18,000 college-educated black residents since 2011, according to Crain’s.

“My guess is that higher-income black folks and more-educated black folks have more reasons to stay and the wherewithal to stay,” Alden Loury, who works for the Metropolitan Planning Council, said to Crain’s. “Their lives are more stable; they’re more likely to live in middle-class communities with better education and employment options and a stable economic base. I think the data also suggests that the city is attracting young tech and other professionals of all races and ethnicities in recent years, including African-Americans.”

The number of Chicago households that earned at least $100,000 in 2016 also jumped to 26.1 percent, which was just 0.1 percent less than the national rate, while in 2006, the city was 1 percent below national average.