Individuals. We show for each grade the 5a) contact-hours in groups per-day, 5c) contact-hours in public activities per-day and 5e) the contact-level-hours per-day added across both groups and public activities without double counting. In each figure a point is plotted for an individual and a box denotes plus and minus one SD centered on the mean value. The red box in 5e) calls attention to the three data points as possible "super-spreaders" within the population surveyed. 5b), 5d), and 5f) show histograms that combine all students in all grades. Per-day values were formed for an average day that incorporated both week days and weekends.
Glass and Glass BMC Public Health 2008 8:61 doi:10.1186/1471-2458-8-61