How to compare open vs closed tickets

How to compare open vs closed tickets

Hello,
We're trying to represent the number of desk tickets opened and the number of desk tickets closed each month on the same graph.

We're looking to create something like this:

With perhaps the blue area being the number of tickets opened, and the grey being the number of tickets closed.

Do we need to create another table that somehow counts each of these values in a row dedicated to a date, then graph that new table?  

Thanks in advance for any ideas!