Cause that's the year I got into kpop. Active at the time groups only.
2015:
2016:
1. f(x) last year being active with the release of ALL MINE and COWBOY.
2. Crayon Pop
3. AOA
4. T-ara
5. Berry Good
2017:
2018:
2019:
2020:
1.
2.
3.
4.
5.
2021:
2022:
As you can see kpop fell off for me for almost 2 years. But now it's back!