For a given row on Sheet1, I use the
SUMIF function to see if the value from the first cell of that row is on a list of historical values in Sheet2.
That will basically summarize all the values on my historical sheet and group them by my A1 cell name on Sheet2.
I need a second condition so that I can group rows by month also, and the
SUMIF does not seem to allow for a second condition or an
AND to concatenate a second clause.