Cumulative percentage comparison by weekday up til last posted day

After getting the cumulative comparison up to date of all numbers, I was trying to figure out how to compare the same weekdays of the month to last year but trying to calculate it up to the last posted day with the same number of days.
For example, if I have more Sundays recorded to date for one year, I would only compare the two years with the earliest Sundays of the month up to the same number of Sundays for each year.

Example of numbers is attached.