The Centre on Regional Democratic Governance is collecting data on regional electoral systems which we define as the rules that translate votes into seats and that govern the conduct of elections. Our aim is to present country profiles and information for each region in more than 20 European countries for 1950-2020 on topics such as electoral thresholds, district magnitude, electoral timing, horizontal and vertical simultaneity with other elections, and so forth. The data will probably be released in 2024 but in case you are interested in a particular region or country you can contact me.