i	j	y
1	1	28.7
1	2	29.3
1	3	28.2
1	4	28.6
2	1	30.7
2	2	34.9
2	3	32.6
2	4	34.4
3	1	31.9
3	2	34.2
3	3	34.9
3	4	35.3