The indicator describes the proportion of persons aged 15 to 16 who have participated in each form of crime at least once during the year. Stealing from a shop or school is included in the statistics for theft. Damage to property includes drawing and writing on walls, damage to property in school and damage to property outside school. The examination of violence includes participation in a fight in a public place as well as assault. With respect to drugs, the use of marijuana or hashish is included.
Only a fraction of crimes are reported to the police and thereby recorded in official statistics. Particularly in so-called volume crime, the proportion of unreported cases is high. To form an accurate picture of the level, characteristics and trends of crimes committed by young people, surveys measuring overall criminality are required in addition to official statistics.
Juvenile delinquency surveys are a nationally representative indicator system measuring the criminal behaviour and victim experiences of young people aged 15 to 16. The population consists of ninth-grade students of Finnish-language upper secondary schools throughout Finland. The survey began in 1995 and has been repeated a total of seven times. The 2016 questionnaire was answered by 6,061 ninth-grade students. In 2012, the system was reformed so that the survey is now conducted using an Internet-based questionnaire instead of a paper questionnaire.