Year 2015:
http://ss.kikimon.net/Y9pMLtX.png

First going down - middle of year going up


Year 2016:
http://ss.kikimon.net/NE0Keg9.png

First going down - middle of year going up


Year 2017:
http://ss.kikimon.net/qZxxCju.png

First being steady - middle of year going up


Year 2018:
http://ss.kikimon.net/WXTCO.png

It's going down... what that means?