http://backpack.tf/classifieds/search/id/5200230e4bd7b80365000003 (1 at 1.6, 1 at 1.7, lots at 1.8, lots at 2)

Proof:

Selling:

2 keys:

http://www.tf2outpost.com/trade/16524908 (1 day)

http://www.tf2outpost.com/trade/16566517 (<1 day, sold 1)

http://www.tf2outpost.com/trade/15857591 (1 month, price has probably changed)

http://www.tf2outpost.com/trade/16556912 (1 day)

http://www.tf2outpost.com/trade/16555380 (1 day)

http://www.tf2outpost.com/trade/16577504 (<1 day)

1.9 keys:

http://www.tf2outpost.com/trade/16576960 (<1 day)

http://www.tf2outpost.com/trade/16589914 (<1 day)

1.8 keys: (Note: 1 key and 5-5.33 ref = 1.8 keys)

http://www.tf2outpost.com/trade/16596278 (<1 day)

http://www.tf2outpost.com/trade/16564770 (<1 day)

http://www.tf2outpost.com/trade/16546297 (1 day)

http://www.tf2outpost.com/trade/16544826 (1 day)

1.7 keys:

http://www.tf2outpost.com/trade/16590673 (<1 day)

1.6 keys:

http://www.tf2outpost.com/trade/16574918 (<1 day)

1.5 keys:

http://www.tf2outpost.com/trade/16568354 (Sold)

http://www.tf2outpost.com/trade/16563708 (Sold)

http://www.tf2outpost.com/trade/16558594 (Sold)

http://www.tf2outpost.com/trade/16541440 (1 day)

http://www.tf2outpost.com/trade/16537670 (Sold)

When combined with the lots in classifieds, there are many 1.8 key sellers. Leaving 2 keys in the range, just adding 1.8.

Thanks for voting : )