How to count intials in a table

I have a table (4 columns) used as a roster for fundraising. The table rows (1st Col) are dates eg; 4-Mar, 11-Mar etc. Columns 2-4 contain a members initials that are rostered for that date. (See below)

What i would like is to be able to have a separate table (pivot table) that will count & give the number of total occurrences, ie; how many times a member is rostered in a particular period (month/year) Ideally this would update as filling out the roster so as to keep the roster spread across members