If column A contains months, column B contains company names, olumn C
contains performance, then in cell D1 (January)

=COUNTIF(B:B,B1) will count how many times company name in B1 occurs in
column B. If company in B1 reported in all 12 month, it will give 12. Filling
down this formula in column D results in

D2: =COUNTIF(B:B,B2) also 12, because B1 = B2 (February)
....
D12: =COUNTIF(B:B,B12) also 12, because B1 = B12 (December)

Say company in B13 reported only from March to December, then
D13: =COUNTIF(B:B,B13) gives 10
....
D22: =COUNTIF(B:B,B22) gives 10

Filtering column D by the criterium =12 hides all rows containing 10 in
column D, so you will see rows for companies which occurs 12 times in column
B.

I hope it's clear now!

Regards,
Stefi

Filling down column D
"Bram" wrote:

> Thanks Stefi for your quick reply but I don't understand your formula
> completely. Maybe my question wasn't clear enough.
> I have a large dataset (over 20,000 rows) with monthly performance of
> certain companies.
> column A is the date (A1-A12 january-december for company 1; A13-A24
> january-december for company 2 etc.)
> Column B is the company name(B1-b12 company 1; B13-B24 company 2 etc.)
> Column C is the monthly performance.
>
> Some companies only reported performance for the months (e.g.) March till
> december. I want to exclude those companies that didn't report performance
> during a whole year.
> You said that I must choose an unused helper column, say D, but what formula
> do I need to type exactly for that whole column?
>
> I hope you can help me one more time
>
> thanks and regards,
>
> Bram
>
> "Stefi" wrote:
>
> > Choose an unused helper column, say C, in C1 enter =COUNTIF(A:A,A1), then
> > apply autofilter in column C and click value 12.
> >
> > regards,
> > Stefi
> >
> > "Bram" wrote:
> >
> > > I have a large dataset of the monthly performance of certain companies.
> > > example
> > > a1:a12 contain January till december of company A
> > > a13:a24 contain January till decmber of company B
> > >
> > > Some companies only have data from March till december. How can I filter
> > > these companies out of the dataset.
> > >
> > > So I only want companies included that reported performance for a whole year
> > >
> > > Thanks!!
> > >