Past 90 days

https://imgur.com/a/JHaq5IH

9 & 10 keys sales are under / too close to buyorders to be included

Sales ranging from 12 keys 25.11 refs ( 12.44 keys -> 12 keys ) to 17 keys

Marketplace sales:

https://marketplace.tf/items/tf2/30672;5;u3027?ssortdir=1

https://marketplace.tf/items/tf2/5021;6

Oct 16

62.99/1.83=34ish keys, very high

Nov 8

39.99/1.79=22ish keys, high

Nov 20

23.33/1.76=13.25 keys, fits in range

Dec 2

23.15/1.7=13.6 keys, fits in range

Dec 14

34.99/1.67=~21 keys, high

Going with 12-17 keys