time group
15  1
10  1
13  1
 7  1
 9  1
 8  1
21  1
 9  1
14  1
 8  1
10  1
19  1
10  1
11  1
 6  1
15  2
14  2
12  2
 8  2
14  2
 7  2
16  2
10  2
15  2
12  2