How much fuel does everyone use each day?
This clearly depends on fuel type, temperature, wind conditions, cooking style, and how many meals are cooked each day.
I take a canister stove (and windscreen), model depending on how many people. We usually cook only dinner, unless it is cold, in which case we heat up water for breakfast. Dinners can be complex, often requiring two pots. Also, we clean up the dishes and sometimes ourselves with hot water after dinner.
That said, we use 12-20 grams/day/person, with 15 grams typical. 20 is for when it's colder and windy, and we heat water for breakfast. 12 is when it's mild and dinner is simple.
This seems to be independent of stove: MSR pocket rocket, Primus micron, Coleman F1 powerboost, and Coleman Xtreme.
I suspect we use more fuel than most.