15vuotiailla

15vuotiailla is a Finnish term used to refer to the group of people who are fifteen years old. The standard orthography in Finnish is 15-vuotiailla, where the hyphen joins the numeral to the noun root and the ending -illa marks the adessive case, indicating “among/at the 15-year-olds.” The variant without the dash, 15vuotiailla, may appear in plain-text contexts or casual writing but is not the normative form.

The term is primarily used in demographics, statistics, education, and health research to denote data concerning this specific age group. It appears in sentences describing characteristics, behaviors, or outcomes among fifteen-year-olds, for example in reports that compare different age groups or examine issues prevalent in adolescence. While the exact phrasing can vary, the core idea stays the same: data or observations about people who have reached the age of fifteen.

In Finland, fifteen-year-olds are commonly associated with the end of the basic-education cycle, as many students are in the 9th grade of peruskoulu around this age. Consequently, 15-vuotiailla data frequently appear in educational statistics, youth surveys, and health research, and they are a standard reference point for analyses of adolescence and early teenage development.

See also: statistical reporting on youth, demographics, and Finnish education statistics. For readers outside Finland, the concept corresponds to the age-based group of fifteen-year-olds used in similar demographic and social research.