Bulgaria is fifth in the world by the speed of its population ageing with drastic changes in the demographic structures expected by 2050.

The data comes from a number of local and international studies, according to Emiliya Voynova, an expert with the "Standards of Living and Social Security" Directorate, cited by the Bulgarian news agency BTA.

The forecast is that by 2050 those age 60 and over will be over 30% of the entire population of the country – a share threatening all social systems with degradation, according to demographic experts.

Voynova further points out the demographic situation in Bulgaria is the most critical among all European Union Member States.

Negative trends include low birth rate, high death rate, low average life expectancy, large migration exodus.

The average life expectancy in the EU is 76 years for men and 82 years for women, while in Bulgaria it is 70 and 77 respectively.

In 1999, the share of Bulgarians under the employment age has been 22%, compared to 15% in 2010.

"We have now an ageing work force without a chance to making it younger by counting only on new births since the number of young people who can have and rise children is going down," the expert says.

In 2011, in Bulgaria, for every 100 employees going into retirement, just 70 young people enter the work force, compared to 100 and 124 respectively 10 years ago.