Hello,

I have many phone book ads for which I am tracking the number of unique calls each month. While I have data dating back to 2014, I would like to keep a YTD total and YTD average number of calls. The problem is that the books are all published in different months—so, if one book is published in March, then its "year" would start in March, vs. a book that is published in July, and so on. In the example attached I highlighted each range I would like to calculate. I know that I could manually change the formula for each month, but there are many more books than I show in the example—I was hoping to find a formula based on an entry in another cell, which is why I included columns D & E (and made C number-formatted). Also, if it's worth noting, I will continue to be adding data to this spreadsheet (i.e., into 2016).

Any advice would be appreciated, thanks!


RG_Example.xlsx