Why is Dominica’s Population Always 70+k

For as long as I remember the population of Dominica on all sources that present a profile of Dominica say we are between 70,000 – 73,000 people. There has been a brain drain and skill drain over the last 3 decades – So how is it we can still maintain a 70+k population? I think we are between 50k – 60k. Especially after Hurricane Maria Dominican has seen most of it’s sons and daughters leave, even those adopted ones (Chinese, Haitians, Spanish).