A	B	Y
1	1	15.5
1	1	16.2
1	1	15.0
1	2	18.7
1	2	15.0
1	2	20.8
1	3	12.0
1	3	15.0
1	3	13.2
1	4	12.4
1	4	10.4
1	4	 9.5
2	1	16.1
2	1	 7.3
2	1	10.5
2	2	 7.5
2	2	 7.2
2	2	10.8
2	3	 5.2
2	3	 9.4
2	3	 5.5
2	4	 8.8
2	4	10.3
2	4	 9.9