Fig. 2From: Sleep-related difficulties in healthy children and adolescentsPrevalence of problematic amounts of sleep-related difficulties by age and gender. Note. Prevalence of problematic amounts of sleep-related difficulties by age and gender in the child sample (age groups 4−5, 6−7, and 8−9) and in the adolescent sample (age groups 10−11, 12−13, 14−15, and 16−17)Back to article page