Unique entries / new entries against historic data

[Leopold2000]

Hi,

Quite a tricky one I'm afraid! I would like a formula that tells me how many NEW suppliers have delivered each month.

For the first month of the year I am using (pls note my excel is in Spanish!):

=CONTAR.SI(B7:B274;">0")

for the second month I do not want to count suppliers who delivered in the previous month. The formula I have used is:

=SUMAPRODUCTO((D7:D1000>0)*(B7:B1000=0))

I have a problem in the third month. THe formula should tell me how many NEW suppliers delivered in the THIRD month, who have not delivered either in the first or the second month.

I have attached the excel for clarity!

Would be amazing any help.

Thanks,

Leo

[daffodil11]

=sumaproducto((f7:f1000>0)*(d7:d1000=0)*(b7:b1000=0))