Hi Frank,

just as an alternatve (very similar of course :-))
=COUNT(1/FREQUENCY(IF(SUBTOTAL(3,OFFSET(A2,ROW(A2:A20)-ROW(A2),,1)),MAT
CH(A2:A20,A2:A20,0)),ROW(INDIRECT("1:"&ROWS(A2:A20 )))))


Yep. Nick has indeed many choices :-)

Regards,

Daniel M.