Throughout the years, the various levels have had different names, number of participants and structure. Generally, the top level has always been a single league, while the lower levels have consisted of a various number of divisions specified geographically and running simultaneously. For instance, up to and including season 2011-12 the second tier of Bulgarian football consisted of two leagues: "East" and "West" divisions of the Bulgarian B Professional Football Group; also, the third level continues to have four divisions (South-West, South-East, North-East, and North-West) that run in parallel.