Take paper weights for what they are. An "average", not based on TIME of year, LOCATION of waterbody, TYPE of water body. So many variables.
As MT and C7 have both stated. I would gues I have caught somewhere near 25 bass over the 20" mark. I consider each of these great fish. Mind you most of the caught out of the same body of water, I have caught a few that were 3 1/4 pounds if I was lucky. Others have passed the 5.5 or 6 pounds mark.
It is understanable judging fish can be hard. I have got an eye for it because I am around fish daily. I will weigh some just to see how close my guess is. Maybe 2 and 3/4. Or 1 and 1/2 pounders. Sometimes my guesses are way off. But if you think about it, if you have a 4.5 pound fish, to be "5.5" pounds, it would take something like 17% of FISH. I'm not good at math by any means, and my numbers may be slightly wrong, but that's alot of fish.
It's a great fish none-the-less.