Sometimes when i click the same person multiple times the count for the achievement dont change, and this one is only for this year or will anual like the kisses Achievements?

I don't know how the achievement count works since I can't bite yet but I was around when a few users were doing a lot of biting initially and I thought theirs counted the same person multiple times?

I'm hoping it'll be annual, but there's really no way of knowing since this is the first year this system was brought in for zombie skins :x I personally think so because if they're going to bring the old skins back once, they might as well bring them back annually imo