Calculate % of total across the date dimension

[Skylerki]

Hi

I am using power pivot over my Analysis Service Cube. I am trying to calculate the % of incorrect data for a business unit for each month to determine a trend. Within the cube I have the following Dimensions and Measures(prepopulated in the cube).

MeasuresTransaction Distinct Count - The count of the records within the transactions table
ItemItem Material ServiceItem Material Service - The indicator showing if the data if a material or service or blank
Transaction DateTransaction-Year-Quarter-Month-DayMonth - The month of the transaction
Transaction DateTransaction-Year-Quarter-Month-DayYear - year of the transaction
Purchase OrganisationCore-BU-SiteBU Name - The name of the business unit

How do I sum the total per month and calculate the % of ItemItem Material ServiceItem Material Service indicators?

I attached what my pivot looks like now.

Thanks
Sky