how to track when Multi-select custom field gets certain value added

hi

I have a custom field with a predefined set of values. I want to track when a particular value was appended to that field and count on how many tickets that value was added for a given period. I want to have a table that reads:

Week 1 - 10 tickets had their custom field "foo" updated by appending the value "bar"

Is that possible?

thanks!