Just a few days ago I used LotW to apply for my 160-meter WAS certificate. I received it today (fast service, thanks ARRL!)
I was surprised to see a fairly low number (1667). Hard to believe that 160-meter WAS is that scarce. I checked on my 5-Band WAS, which was issued in 2014, and it was #3167. One would assume that most folks with 160-meter WAS probably already have 5-band WAS, so only about half to on to complete their 160-meter WAS. After putting in crazy hours on 160-meters the last couple of years, I can understand why.