temps (durée) (1) saison (1) santé publique (1) association (1) analyse (1) éducation (1) âge (1) comparaison (1) enfant (1) Education (1) Comparison (1) Children (1) Preschool children (1) Week (1) Time (1) Sun--Rising and setting (1) Social groups (1) Regression analysis (1) Public health (1) Exercise (1) Evidence (1) Ethnicity (1) Education (1) Design (1) Daylight (1) Day (1) Children (1) Average (1) Older people (1) Age (1)