Left: time evolution of the average cumulated time spent by a student in contact with other students during the study.

The average total time is displayed in black, the average time spent with students of the same class in blue, and the average time spent with students of other classes in red. Right: time evolution of the average number of distinct persons with whom a student has been in contact since the start of the data collection. The average total number is displayed in black, the average number of individuals of the same class in blue, and the average number of persons of other classes in red.