Have you searched the Forums for an answer? This comes up quite a bit, and you may stumble across an existing answer.
I recommend checking this out:
Your options will likely depend on how your data is structured. For example, if every entry has a NULL or 0 value, that's going to be easier to work with, as opposed to instances when the month data simply doesn't exist.
thank you very much for your response!
It is kind of the solution. The last step would be to calculate the average year on year so putting the month out...but then unfortunately it doenst work anymore and tableau puts the months back in