Why did Sussex County, NJ decline in population?

[I spent the winter writing songs about getting better]

I know that rural areas lost population almost everywhere, but Sussex County is more like NYC exurbia which is what drove it very immense growth in previous decades, and it's not like easy or cheaper housing closer to NYC popped up in the last decade. What happened?

[Builder Refused]

Well the average family size decreased from 2000 to 2010, the land prices seem to have inflated at least from 2002 to 2007, it’s a very wealthy area with 40% of the workforce  in management, business, science, and arts. Dairy farms have decreased in size and profitability, so my guess is more sprawl plus more people who tend to have larger families moving out and being replaced by a lawyer and a sociology teacher with one or two kids. That’s just a guess, I based it off some analysis Bread Price Fixer did on Chicago with a similar home size decline, but I think population increased in that specific part of Chicago?