Count number of times a box is ticked in Access 2003

[eggyuk]

Hi

I've got a database that has among other fields Test Date and Cont of Care (Yes/No). I want to be able to count the number of times Cont of Care is ticked and then group it by the Month of the test. Everything I have tried so far gives me all the tests done regardless of whether it is ticked or not or I get nothing. Would any kind soul be able to explain what I need to do?

Thanks