The situation has drastically changed over the past 40 years. In early 70s all countries in the study besides Germany recorded albums in their local language on more than 65% of occasions, however as of 2015 all of these countries were now doing so less than 50% of times. Germany stands out as having already a low share of releases being recorded in german in early 70s.
Another notable trend is the major decrease seen over the last 10 years, and most notably in Turkey. This seems to coincide, as you can see on the second graph, with a major drop in number of records being released overall that started in 2007. And this drop impacted more heavily the number of recordings in local language. One could probably conclude from this that the music industry crisis led artists and/or companies to give a preference to singing in English as this would allow them to have access to a larger audience.
