I have three fields in a table, and want to determine the total of the
occurrences by a certain time period. The data I have looks like this.

FGC RDate Occurrences
81 2009/01 1
81 2009/02 1
81 2009/03 1
81 2009/04 1
81 2009/05 5
81 2009/06 84
81 2009/07 1
81 2009/08 6
81 2009/09 3
81 2009/10 1
81 2009/11 5

And I want it to look like this

FGC 81

Less Than 3 Months 9
3 Or More Months 91
6 Or More Months 7
9 Or More Months 2
12 Or More Months 0

The month that the results are based off of is 2009/11. For this example, I
am using a specific month, but for future use the month will be determined by
Date() converted to yyyy/mm.
Any help would be greatly appreciated.

Thanks