Most people live in towns, of which the capital, Copenhagen, is the biggest. The three second biggest towns are Aarhus, Odense and Aalborg. There are approx. 2.9 million families, of which more than 645,000 have children. Around 1.4 million adults live alone; approx. 118,000 of these have children. In 1999, the population growth increased by 18,800 persons, of which 11,000 was a result of net immigration to Denmark. Immigrants and their descendants make up 6.8% of the population in Denmark. In 1998, over one million persons were enrolled in the formal education system. To this should be added 152,800 student full-time equivalents enrolled in public-sector adult education. The level of educational attainment of the Danish population is increasing all the time. In 1999, 1/3 of the population of 15-69-year-olds only had basic school as their highest level of educational attainment. The unemployment is on the decline. In 1998, the total unemployment rate was 5.6%. In 1998, the largest employment sectors were: public and personal services (34.9%), trade, hotel and restaurant (18%), industry (17.7%) and finance etc. (11.4%).