Add a count number in relation to column

[James_Hockley]

Im looking for the formula to add a 'count number' in column E in relation to Col A EVENT_ID.

So in the first group 1928855182 i have 7 instances and number them in a first come first served basis.

Thanks in advance.

[#2 · Accepted solution]

@James_Hockley 

=COUNTIF($A$2:A2,A2)

This formula returns the intended result in my sheet.

[#3]

PERFECT, thanks very much