Nashville is growing, but most of it isn't, the latest released Census data show as counties across the state and nation prepare for the 2020 U.S. Census count this spring.

Davidson County grew by nearly 46,000 people between 2013 and 2018, a larger gain than any other county in Tennessee.

But most of that growth showed up in a relative handful of tracts either to the southeast, along the border with Rutherford County, or downtown. Countywide, 80 percent of tracts saw no significant change in population.

Rutherford and neighboring Williamson County, which posted the next two largest population gains in the state, grew more uniformly, by nearly 37,721 and 29,713 residents, respectively. Just less than half of Rutherford's 49 tracts saw significant growth, most in the county's western half. Growth was more evenly distributed in Williamson, where 57 percent of the county's 37 tracts showed significant growth.

Shelby County, long the state's most populous county and home to Memphis, gained a modest 4,086 residents for a 2018 total of 937,005. Davidson remains the state's second-largest county, with 684,017 residents.

"Most people know that the Nashville area is growing, but probably fewer realize how patchy that growth is," said Ken Blake, a data journalism professor in Middle Tennessee State University's School of Journalism and Strategic Media. Blake produced the analysis using figures released in December by the U.S. Census Bureau's American Community Survey.

"Tract-level growth patterns matter, though, because they can end up influencing things like where local governments decide to build new roads or add new schools," Blake added. "They also can show where tree canopies and green spaces are disappearing, and they can hint at which areas might grow next."

Blake has produced an online, interactive map showing which tracts in Davidson, Rutherford and Williamson counties have seen significant population changes.

Statewide, eight counties – Davidson, Rutherford, Williamson, Knox, Montgomery, Hamilton, Sumner, and Wilson – each gained more than 15,000 residents since 2013, data show. The ninth-ranked county, Maury, gained a notably smaller 7,995 residents, and the rest either gained fewer or lost residents.

For example, Lauderdale County, on Tennessee's western border, north of Memphis, dropped from 27,794 residents in 2013 to 26,297 in 2018. The 1,497 loss marked the largest for any county in the state during the time period.

The 2020 census count begins this spring, with households receiving invitations via mail beginning in mid-March in advance of the April 1 Census Day across the nation. For the first time ever, respondents can fill out the questionnaire online while also having the options of phone and mail. More information can be found online at www.2020census.gov.