According to updated figures released April 29, 2019 by the Wisconsin Department of Justice (DOJ), Wisconsin marijuana possession arrests in 2018 increased 2% from 2017 from 17,048 to 17,392 , while state marijuana sales arrests dipped 2% from 1,867 to 1,822.

Previously, DOJ data from 2017 revealed that arrests for possession of marijuana increased from 16,245 to 17,022 from 2016 to 2017, an increase of 5%. From 2015 to 2016, pot arrests had gone up almost 9%, from 14,930 to 16,245. Together those increases represent a 14% increase in state pot arrests from 2015 to 2017.

Arrests for sales of cannabis also increased 4% from 2016 to 2017, up from 1,797 to 1,870 arrests.

I'm assuming the slight discrepancies between the 2017 and 2018 figures are due to later adjustments in the totals.