Elementary education has been compulsory since 1814 and is, for the most part, free. All children must attend school from age 7 to 16. Primary education consists of a nine-year comprehensive school. In the 1995 school year Denmark had 336,690 students enrolled in primary schools. All students may continue school through its tenth year, and gifted students are encouraged to continue their studies beyond that point. Denmark’s adult literacy rate is 99 percent.