effort Type Subject
1      12   T1       1
2      15   T2       1
3      12   T3       1
4      10   T4       1
5      10   T1       2
6      14   T2       2
7      13   T3       2
8      12   T4       2
9       7   T1       3
10     14   T2       3
11     13   T3       3
12      9   T4       3
13      7   T1       4
14     11   T2       4
15     10   T3       4
16      9   T4       4
17      8   T1       5
18     11   T2       5
19      8   T3       5
20      7   T4       5
21      9   T1       6
22     11   T2       6
23     11   T3       6
24     10   T4       6
25      8   T1       7
26     12   T2       7
27     12   T3       7
28     11   T4       7
29      7   T1       8
30     11   T2       8
31      8   T3       8
32      7   T4       8
33      9   T1       9
34     13   T2       9
35     10   T3       9
36      8   T4       9