Hi Fione,
As you mentioned, you have created Year , Month parameters, I think you are trying to give year values as 2013 to 2015 and in month parameter you are selection Jan - Nov.
Since your month parameter range selection is only 11 months and Dec. is not included so, it is not fetching Dec. month data from all the years.
Instead of creating two parameters Year and Month you can create one parameter with date range, it will help you to filter data based on your start date 01/01/2013 to 11/30/2015.
Thanks,
Sastry