Rex Hudler is looking at a ten$-$year security pays $$3,850$ a year at the end of each of the next five years $($t $=1,2,3,4,5).$ After the fifth year, the security pays some constant cash flow at the end of the next four years $($t $=6,7,8,9).$ The security sells for $$32,400$ and promises a rate of return of $4\mathrm{.}6\%$ compounded annually. What annual cash flow does Rex's security pay for years $6$ through $9?$