Apparently high numbers of fentanyl users (article from 2012 which more or less coincides with the big spike in the graph) https://www.bbc.com/news/world-europ

Apparently high numbers of fentanyl users (article from 2012 which more or less coincides with the big spike in the graph) https://www.bbc.com/news/world-europe-17524945 https://www.bbc.com/news/world-europe-17524945