Before the year 2000 the population of Cook Island was modeled by a logistic equation $P^\prime=r(C-P)$ with growth rate $r={2}$ and carrying capacity $C={8000}$ and time t in years. But, starting in the year 2000, 5 citizens of Cook Island left every year to become mathematicians, never to return. Now what differential equation models the population $P$ of the island? $0 =$