Sequential count issue

I am trying to produce a sequential count of column AD if the cell value is Yes. Using the formula provided I am able to get a count but "2" is skipped. I get a count of 1, 3, 4 etc.

Posed in cell AE3 and copied down.

=IF(AD3="Yes",SUM(IF(COUNTIF(AD$1:AD2,AD3)<>1,0,COUNTIF(AD$1:AD2,AD3)),AE2)+1,0)

Jim O

Not sure if you need that long-wounded formula. Simply use..

=IF(AD3="Yes",COUNTIF(AD$1:AD2,AD3)+1,0)