A value around 29.2 cm is typical (50th percentile) for males in this age group.
Scores above about 33.3 cm fall near the 75th percentile or higher, indicating above-average performance. Scores below about 25.7 cm 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.