Millennials and others earning less than $30,000 a year are moving out of Orange County – where rent averages $1,753 a month – at higher rates than would be expected, an analysis shows.

A data scientist at real estate website Trulia drew that conclusion after reviewing earnings and other demographic data for people who’ve left the county and other pricey U.S. metro areas.

The study, including San Francisco, Los Angeles, New York, Chicago, Silver Spring, Md., Washington, D.C., San Jose, Oakland and San Diego, was largely based on data from the 2014 five-year U.S. Census American Community Survey.

The analysis began with an assumption that if households in a metro area fall into certain income and other categories, those opting to leave would reflect about the same percentages. But they didn’t.

The study found:

– In Orange County, the share of households earning $30,000 or less was 13.1 percent. But the $30,000-and-under slice moving away hit 24.3 percent. In Los Angeles County, those households counted as 21.5 percent of the population and 32.2 percent of those moving.

– Millennials – 18- to 34-year-olds – in Orange County made up 20.6 percent of households, but 46 percent of those moving. In Los Angeles County, the respective slices for millennials were 24.4 percent of the population and 48.8 percent of those leaving the area.

– In all the metros studied, households with $30,000 or less moved out at the highest rate. Those earning more than $150,000 a year moved away at the lowest rate, while those making $120,000 to $150,000 represented the smallest group leaving.

– Millennials represented the largest share of all age groups leaving pricey metros, at more than 51 percent.

In Orange County, more than 101,000 low-income households cannot find affordable rentals, according to the San Francisco-based nonprofit California Housing Partnership Corp.

A shortfall of 50,000 to 62,000 housing units could cripple Orange County employers’ ability to recruit and retain a capable workforce, the Orange County Business Council reported in its 2015 Workforce Housing Scorecard.

Asking rents for Orange County apartments averaged $1,753 a month during the first quarter of 2016, according to Reis Inc., a real estate and economic data firm. That’s up 3.7 percent or $63 a month from the same quarter in 2015.

In Los Angeles County, asking rents hit $1,630 a month in the first quarter, up $85 or 5.5 percent from a year before. In the Inland Empire, asking rent totaled $1,193 a month, up 3.6 percent or $41 a month.

See more Trulia results here