data categorized by industry code

[soungl]

Hi, I'd like your advice what data structure would be best for my situation. Thank you in advance.

I have a data set classfied by multiple criteria like the following.

j (area) i (industry) year E
001 11 2008 10
001 111 2008 5
001 112 2008 1
001 113 2008 3
003 11 2008 17
003 111 2008 3
003 113 2008 12
001 11 2009 10
001 111 2009 4
001 112 2009 1
001 113 2009 3
003 11 2009 16
003 111 2009 3
003 112 2009 1
003 113 2009 11
.
.
.

And l'd like to do the following type of operations for each year.

LQij= (Eij/Ej)/(Ei/E)

Ej is the total E in area j (or the sum of all E in the same digit industry code in area j)
E is the total E in the reference area