A value around 39.9 cm (15.7 in) is typical (50th percentile) for boys in this age group.
Scores above about 45.1 cm (17.8 in) fall near the 75th percentile or higher, indicating above-average performance. Scores below about 34.8 cm (13.7 in) fall near the 25th percentile; about 75% of the reference population scored higher.
These percentiles come from a countermovement jump on a Leonardo Mechanograph force plate, which derives height from the ground reaction forces during the push-off. Field jump-and-reach results, such as a Vertec or Sargent test, are not interchangeable with them. The study authors note the survey's health focus may have recruited fitter children and adolescents.