I have two columns of dates, a year and a month, non sequential, like this:

1994 Jan
1990 Jan
1993 May
1994 Apr
1994 Jan
1991 Nov

Etc.

I want to be able to count the number of times each month/dat combinations
appears. For example, How many 1994 Jan combinations do I have (2) how many
1993 May (1) etc.

Is there a way I can do this using countif?