I'm not an fan of AC's fuel surcharge (YQ) but out of curiosity, I took a few minutes to crunch some numbers.

I bought a ticket yesterday, YVR HKG, paid $262.40 for YQ, which appears to be the same regardless of class. So $131.20 each way.
The flight is on a B773 with a capacity of 349 PAX. If there was a butt in every seat AC would rake in $45,474.70 in fuel surcharges.

I admit, this is simplistic and crude calculation, so if anyone has better numbers, please be my guest.
All the numbers I used were found using Google. I also avoided forum type information where people tend to speculate.
This is guesstimate - I'm not an accountant, I bad with numbers and I'm probably way off (what fun).

Fuel burn @ 16 litre/km for B773
X 10460 km = 167,360 litres
X $1.58/litre Jet Fuel (calculated from $6/Gal USD)
= $264,429 Total Fuel Cost
(-) YQ collected $45,474
(=) AC's Fuel Cost $218,955

I'm not sure if AC Cargo charge YQ on cargo shipments. If they do, that's additional money into YQ pot.
I thought that perhaps that the YQ might come close to covering the total cost of fuel for the flight, but if my calculations are anywhere close, it's around 17%.

(I ran out this morning, I wasn't finished writing the post. Shut the computer down, came but somehow my post got submitted.)