cane bay aerial Apr2017 (copy) (copy)

Charleston County residents are most likely to move to Berkeley County. File photo of Cane Bay in Berkeley County. Wade Spees/Staff

The Charleston region continues to grow like crazy, to the tune of 38 new people to the area a day.

Much of that growth is going to Berkeley and Dorchester counties, thanks to their cheaper costs of living and larger inventories of developable land than Charleston County.

Unsurprisingly, then, these two counties are the most common places that people moved to when they moved out of Charleston County. Here's the breakdown of the most recent Internal Revenue Service data: 

These numbers aren't perfect because they rely on tax returns. If you filed your taxes in Charleston County in 2015, and then filed in Berkeley in 2016 then you'd be on that top bar. That means they don't count people who didn't file tax returns, which includes many people who earn $10,400 or less per year. 

When Charleston County residents move out of the area, they're most likely to be moving to Columbia, Greenville, Charlotte or Myrtle Beach. 

Since it's IRS data, we know something about how much these movers earn. Charleston's wealthier residents who leave the county are most likely to move to Greenville, Atlanta or Charlotte (or at least they were last year). Here's those same counties, sorted by average income: 

Folks who moved from Charleston County in 2015 to Berkeley County in 2016 earned, on average, about 18 percent more than people who moved to Dorchester County. 

There is a little bit of an affordability story in these numbers too — about 27 percent more people moved from Charleston to Berkeley County in 2015-16 than vice versa. These trends are backed up by recent numbers released by the Census Bureau, which showed that while Charleston County's growth is finally slowing down a bit (while definitely still growing), Berkeley and Dorchester remain in the top five counties statewide for growth. 

Follow Kelly Poe on Twitter @kelly_poe.