 Bulgaria is in a state of demographic crisis . It has had negative population growth since the early 1990s , when the economic collapse caused a long @-@ lasting emigration wave . Some 937 @,@ 000 to 1 @,@ 200 @,@ 000 people — mostly young adults — left the country by 2005 . The total fertility rate ( TFR ) was estimated in 2013 at 1 @.@ 43 children born / woman , which is below the replacement rate of 2 @.@ 1 . A third of all households consist of only one person and 75 @.@ 5 per cent of families do not have children under the age of 16 . Consequently , population growth and birth rates are among the lowest in the world while death rates are among the highest . The majority of children are born to unmarried women ( of all births 57 @.@ 4 per cent were outside marriage in 2012 ) . 
