Eight groups - Gp1, Gp2, Gp3., Gp4, Gp5, Gp6, Gp7, Gp8 - are either involved in Occupation_1 or in Occupation_2.
Every so often, I have to give the totals.
(How many Gp1s in Occupation_1, and in Occupation_2 etc.
How many Gp2s in Occupation_1, and in Occupation_2 etc etc.).
I get by with a...