Help with Measure to pull a point in time based on Matrix

I have a matrix where I have 2 different dates. One set of date is in my rows and the other is in the columns.

I am trying to write a formula that pulls the first number in each row. 

Example: I want to use the first value in each row as a divisor for each month after.

So 1/1/2019 would be 10/10, 2/1/2019 would be 8/10, 3/1/2019 would bw 6/10.... etc

then for 2/1/2019 in my rows I would start with 2/1/2019 = 20/20, then 3/1/2019 would be 18/20 and so forth

Any suggestions on how I could write a DAX expression to always pull these values as my divisor? 

Any help is appreciated.