Don't know about your situation but a few years ago our coyote population took a pretty good dip compared to normal. Lot less pups in the population. That year I was definitely dealing with a higher percentage of population that been through a season or to and had caught on to the game so to speak.
I've done a fair amount of testing and am a strong believer it's easier to get a coyote to work a test set that a real set. Not that testing isn't valuable and they will definitely show you what they like the best but they sure aren't as easy to get caught as they are to share their opinion.
Something was definitely up. I talked to a few local folks who are way better than me at trapping coyotes and they acted like their numbers were about normal. I do know that at least one of the places I trap with excellent habitat (various age clearcut) seemed to have a lot fewer coyotes than last year. The tracks in the road told me they were coming through every 6-10 days instead of 2-3 like last year. As much as I would like to chalk it up to putting a hurting on them last year, Im not sure that I believe in myself that much. Rabbit population seems a lot lower here this year as well if that plays into it for any reason.
DH still made up the bulk of my catches, but they were probably 90% of my total sets so I would expect nothing less. Last year I couldnt keep animals out of dirtholes so I just kept pouring it to them. This year made me rethink the need for a backup plan