Rigged numbers most likely. The only other explanation is that it is filling up with illegals. The good people are all leaving NYC. Many are leaving NY all together.
Other than my fiancée, everyone I know is back. I don’t know what you mean by “good people,” please explain what you mean.
I expect that the census numbers provided make use of statistical smoothing to make up for reality - people moving out or dropping out.
NYC would have been better off if the descendants of the original Dutch settlers would have stayed rather than gotten on wagons and moved west in the mid-19th when all the poor illiterate and violent Irish moved in and brought their corruption, but that is just my opinion. ;)