How to get a count based upon a grouping

I need to query a table similar to the one below. Basically I need to group the records below by the number of records
in each month. So the query would produce this result from the CustomerPurchases table. I can have the query display the month/year however how do I get the counts, of the number of records per month?
Purchase Per Month
5/2016     3
6/2016     1
7/2016     4

CustomerPurchases
1 | 2016-05-01 12:33:44:187  |  Bartermore
2 | 2016-05-13 12:30:00:000  |  Drake
3 | 2016-05-31 01:22:11:187  |  Sami
4 | 2016-06-01 12:33:44:166  |  Gabak
5 | 2016-07-01 11:28:44:144  |  Laster
6 | 2016-07-11 12:34:45:186  |  Gobo
7 | 2016-07-15 12:33:44:187  |  Darmore
8 | 2016-07-15 12:33:44:175  |  Grabson