Primary 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 9-year comprehensive school. In the 1996 school year Denmark had 337,000 students listed in primary schools. All students may continue school through its 10th year, and gifted students are promoted to continue their studies beyond that point. Denmark’s adult literacy rate is 99 %.