{"0":{"students":220,"hour_total":286,"exercise_total":218,"hours":[null,176,11,3,1,1,null,null,6]},"1":{"students":176,"hour_total":2421,"exercise_total":2748,"hours":[null,6,3,3,4,9,5,8,13,4,28,1,14,2,3,20,2,4,3,null,15,1,1,null,6,5,null,1,2,null,8,null,null,null,null,1,null,null,null,null,2,2]},"2":{"students":143,"hour_total":1862,"exercise_total":1343,"hours":[null,1,1,5,5,8,8,3,10,7,21,1,11,6,1,11,7,2,4,null,10,null,null,null,4,3,1,null,null,null,3,2,null,null,null,5]},"3":{"students":99,"hour_total":1397,"exercise_total":679,"hours":[null,1,2,1,2,4,7,5,10,1,17,1,3,3,5,7,2,1,1,null,8,null,1,null,3,3,1,null,null,null,1,null,1,null,null,8]}}