Patient	After	Before	Difference
1	3	6	-3
2	1	2	-1
3	0	2	-2
4	0	3	-3
5	2	3	-1
6	1	4	-3
7	2	2	0
8	1	5	-4
9	0	1	-1
10	4	6	-2
11	1	6	-5
12	4	4	0
13	8	8	0