Domenic, your formula, just does a continous numerical count of all records.
Dufus, your formula counts correctly, however, after x, when another N record appears, then recount. see expanded example.
example
T4:T15 = N,N,N,N,N,N,N,Y,Y,Y,N,N
formula Result
U4:U15 = 1,2,3,4,5,6,7,8,9,x,x,1,2
thanks