Price Impact Measure Help Needed

Hi, first  
of all, thank you for your reply.

I'm unable to share the file I'm working with currently.

This measure would be used in conjunction with a Month Year Slicer that allows users to select the period that they want to see the Price Impact for.

This would therefore mean CY = The sales in current Month Year selected vs Same Period Last Year.

There are also different customer types (called activities) in my images below, however, all sales figures (sales and quantity sold) are pulled from the 1 table for all customer types, item types etc.

Please let me know if you require anything else and thank you again for helping me with a formula to capture the 3 conditions from my original post.

Here is an example of what slicers I have / how the report looks currently. I need a Price impact measure to add in to the end of this table.