The Open Data Barometer is a global measure of how governments are publishing and using open data for accountability, innovation and social impact.
In the 4th edition 2017 of Open Data Barometer published on 23 May 2017 for the firt time is included Bulgaria and ranks 40 among 114 countries:
http://opendatabarometer.org/doc/4thEdition/ODB-4thEdition-GlobalReport.pdf