How to count a column if it matches data from another column in seperate rows.

I have two columns with dates. Colum A has the date of the deadline of a document while column b has the day it was sent. Column X will display the difference if its a positive integer ( i.e. if the document has been sent after the deadline). Now i have another column Y which displays the month as an integer of when the document was actually received.

Now i need a counter which will count the number of instances a positive integer is registered in column X according to the month in column Y. I have been trying everything but cant figure a simple way to do it. Im doing this so i can be able to see how many documents are sent after the deadline per month.

Thanks a lot