What is the average level of players in your local area? To find this, make a list of everyone’s levels in gyms/raids, then add them all up, and divide that sum by the number of players you noted.
My area is about level 31. (I’m almost level 34)
I think the average is 29-30. Lots of mid low 20s, with some high 20s and low 30s. Only a couple players over 35.
Lots of changes where I live. Before, the 2 gyms nearby where occupied by level 30-38 trainers.
Nowadays I don’t see any of them anymore, not one. All new trainers level 20ish.
Interestingly enough, the first minute of the first day the gyms were
functional again, the brand new gym in front of my home got occupied by
not one but two Lv.40 players whose names (apart from being the same
with numbers at the end, very close friend I guess, and hardcore players
too 
) I’ve never seen before… And two other, Lv.38 and 37 respectively (these I recognized)
I play mainly in two different places: around my home and in the lunchbreaks at job
Around home (close to city center) the average level is prety high (33, as my own level) so claiming gyms is quite a challenge unless I manage to co-ordinate with other instinct player (not very often though…)
In my workplace area, the average level is 26, which means that I can solo gyms with ease 
Average seems to be about 30.
At least in the raid groups I frequent
Level 38 BTW