I think the DMV has a “native” population loosely defined as people born in the area still living there around 30 - 40%. This is on the low end nationally for large metros. It pales in comparison to more “townie” spots in up state New York or the Midwest for instance, but is lower nationally than most other big cities, approaching Florida levels. Though there may be some noise in the data because it defined if you’re living in the state you were born in, so if someone is born in VA and moved to MD it may be counting that as a transplant, but hard to tell from the data:

https://www.promoverreviews.com/moving-resources/us-cities-most-transplants/#Wrapping_Up:_Major_Insights_and_Conclusions