KE30 report is missing period data

Hi,

I am New to CO and User came up with issue with KE30. User is executing KE30 for 12 months data, if we execute report for 2012 it is showing data for all periods and if 2013 it is showing data only for first 3 periods that is for jan, feb, march rest showing '0's. as a abaper how to proceed in this case.what would be the problem.

Thanks,

Venu