Help with Excel

[nicolecrichton]

Hi, so I have data on patents by year and industry code and I would like to group certain industry codes together and sum the number of patents relating to those codes but still separate by year and grouped industries. For example, I would like to combine the industry codes 10, 11, and 12 as one group and sum the patents, and combine codes 13, 14, and 15 as one group and sum those patents for each year. How would I go about doing so? Any help is appreciated. Below is part of my excel sheet for reference:

2008	10	84
2008	11	17
2008	12	2
2008	13	27
2008	14	7
2008	15	1

2009	10	78
2009	10.5	3
2009	11	10
2009	12	2
2009	13	13
2009	14	2

[#2]

@nicolecrichton 

=SUMPRODUCT((($B$2:$B$13=$F$4)+($B$2:$B$13=$G$4)+($B$2:$B$13=$H$4))*($A$2:$A$13=E5)*$C$2:$C$13)

Maybe with this formula for the data layout of the example. In cells F4, G4 and H4 you can dynamically enter up to 3 industries that you want to group and sum.