I want to show the cross tab report with percentage value. Actually i want to know the machine utilization in a month which means how much percent the machine was utilized in a month.

ex: i have 4 machines and each machine will run in daily basis for the whole month based on the planning, but some machines break down in a month.

percentage formula: (Plan days/Days in month)*100
Jan Feb March April
Machine-1 80% 70% 65% 89%
Machine-2 10% 20% 10% 20%

I tried the report i am getting only count of plan days but i am not sure how to apply the percentage formula.

please help me.