I have a large table that has a numerical count of observations for every day
of the year for 5 years. however i am trying to sum that data by month for
each year in a differenet table. The data is in this following form:

Year Month Day Amendment Count
2003 1 1 65596
2003 1 2 64991
2003 1 3 85596
2003 1 4 81660
2003 1 5 76551
2003 1 6 80182
2003 1 7 85333

I have been trying to make it work with Vlookup but that just returns a
single number and not the sum for that month and particular year as i was
trying to achieve. Is it possible?

Thanks in advance.