No can do.

Sales

Sale 1: Sold for Refragmenting Reality Citizen Cane

https://backpack.tf/profiles/76561198337734785#!/compare/1595894400/1596067200

https://backpack.tf/profiles/76561198274503484#!/compare/1590796800/1595980800

Sale 2: Sold with 6 keys for Vivid Noir (20.5 keys)

https://backpack.tf/profiles/76561198068806552#!/compare/1591660800/1591747200

https://backpack.tf/profiles/76561198060730062#!/compare/1591747200/1591833600

20.5 - 6 = 15 keys~

Sale 3: Sold for 17 keys

https://backpack.tf/profiles/76561198060730062#!/compare/1592524800/1592611200

https://backpack.tf/profiles/76561198112141269#!/compare/1576108800/1594339200

Buyout was close.

https://bot.tf/stats/listings/MQ0J0O2P

Sale 4: Bulk

https://backpack.tf/profiles/76561198112141269#!/compare/1594684800/1595721600

https://backpack.tf/profiles/76561198080179568#!/compare/1594598400/1594684800

Sale 5: Sold for 15 keys

https://backpack.tf/profiles/76561198080179568#!/compare/1596067200/1596153600

https://backpack.tf/profiles/76561198063514725#!/compare/1555545600/1596499200

Sale 6: Untrace

https://backpack.tf/profiles/76561198043444428#!/compare/1596844800/1596931200

https://backpack.tf/profiles/76561198257383813#!/compare/1596326400/1597795200

https://backpack.tf/item/269560556

Sale 7: Untrace

https://backpack.tf/profiles/76561198337734785#!/compare/1595894400/1596067200

https://backpack.tf/profiles/76561198043444428#!/compare/1595462400/1596067200

Buyout was about 15 keys~

Sale 8: Untrace

https://backpack.tf/profiles/76561198131983415#!/compare/1595808000/1596499200

https://backpack.tf/profiles/76561198337734785#!/compare/1595635200/1595894400

Buyorder was 12 keys~

https://bot.tf/stats/listings/4P0Q6P5E

Sale 9: Bulk

https://backpack.tf/profiles/76561198797318492#!/compare/1593475200/1593648000

https://backpack.tf/profiles/76561198131983415#!/compare/1592956800/1593820800

Other exchanges, such as tradebacks, mannco, scrap, qs store, and etc.

https://backpack.tf/item/9052191851

Sale 10: Sold for 17 keys

https://backpack.tf/profiles/76561198051930593#!/compare/1593388800/1593475200

https://backpack.tf/profiles/76561198797318492#!/compare/1593388800/1593475200

Sale 11: Untrace

https://backpack.tf/profiles/76561198305494036#!/compare/1593302400/1593388800

https://backpack.tf/profiles/76561198051930593#!/compare/1593216000/1593388800

Buyout was 15 keys

https://bot.tf/stats/listings/466JX8VR

Marketplace

https://marketplace.tf/items/tf2/324;5;u15

July

$39.99 on July 7 (39.99/1.98 = 20~)

https://manic.tf/keyprice/?at=2020-07-07

https://backpack.tf/item/7956356184

Listings during the time: https://bot.tf/stats/listings/M0OPEO0Z

August

$39.99 on August 2 (39.99/1.9 = 21~)

https://manic.tf/keyprice/?at=2020-08-02

Classifieds

https://gyazo.com/42b8c5b685c1539093642bea53d7f37c

Buyers are up to 14.5 keys~.

Summary

Sales at 15, 15, 17, and 17. Two untrace sales with buyouts of 15.

Marketplace sales at 20 and 21.

Conclusion

Past sellers show that 20/21 is a bit high, going to exclude them.

Going with 15-17 here.