Women accounted for 51.5 per cent of the population. There were 1,064 women per 1,000 men in 2006. The urban population totalled 5,425,300 people (70.6 per cent). The rural population was 2,254,000 people (29.4 per cent).
Ageing was the predominant change in the age structure, which accounted for a rise in the average age of the population. It was 39.9 years in 2000, 41.2 years in 2005, and 41.4 years in 2006. The rural population had a higher average age than the urban population.
The working age population totalled 4,820,000 people in 2006 (62.8 per cent), up by nearly 6,000 people from 2005. The increase was smaller than in previous years because the retirement age for men was 63 years and did not increase by six months a year, as is the case with women.
Bulgarians over working age numbered 1,740,000 in 2006, down by 22,000 in a year. The decrease is due to death, as well as due to the shift in the retirement age, which meant that part of this group joined the working age population.
The population under working age is showing a downward trend. It was down by 23,000 from 2005 and numbered 1,120,000.
Of the 74,495 children born in 2006, 73,978 were live births (99.3 per cent). The number of live births was up by 2,903 from 2005.
Of all children born in 2006, 38,108 were boys and 35,870 were girls (1,000 boys per 941 girls).
The children born in towns numbered 55,043, compared to 18,935 children born in villages. A total of 10.1 children were born per 1,000 urban population and 8.3 children per 1,000 rural population.
The birth rate in Bulgaria is at the same level as in Italy, Greece, Hungary, Austria, Poland and Switzerland. Germany, Latvia, Lithuania and Slovenia have lower birth rates.
The absolute number and relative proportion of children born out of wedlock have trended up in recent years. For 60 per cent of these births there is information about the father, which means that not all of these children live outside a family. The father is unknown in 20.3 per cent of all births.
The number of deaths stood at 113,438 in 2006, close to the 2005 level of 113,374 deaths.
Marriages were 32,773, down by 728 from 2005. Of them, 79.6 per cent were registered in towns. As to divorces, at 14,828 their number was close to the 2005 level of 14,676.