4 in 1979, 4 in 1983, 1 in 1985. None since.
On the WHC 1979, 1980, 1981, 1982, 1985, 1986, 1987, 1988, 1989, 1990.
The Communist party of Bulgaria stepped down in Dec 1989 ........ since when no doubt attention has been concentrated elsewhere.
The T LIst of 13 sites is still dominated by ones added in 1984 but there were additions in 2004 (1) and 2011 (4) so maybe the country is awakening from its WHS slumber. It also extended Pirin in 2010.
It was certainly vastly over-represented in the early years -but I guess it had an enthusiastic department for whom such matters were a way of escaping the daily Communist drudgery and no doubt it was seen as having a propaganda value too.
I have been to a few of its T List sites but am not aware of any great gap which they would fill. Perhaps they will have to await the end of Bukova's "reign" as UNESCO Director General beforre it would be "seemly" to make another inscription? (she has 4 years starting 2009)