method	x1	x2	y
a	4.1	5.3	3.95
a	4.6	5	4.35
a	4.8	6	4.55
a	5.4	6.2	4.7
a	5.2	6.1	4.9
a	5.7	5.9	4.9
a	6	6	5
a	5.9	6.1	5.5
a	4.2	5.2	4.05
a	4.6	5	4.3
b	5.5	6.2	5.1
b	5	7.1	5.3
b	6	7	5.5
b	6.2	6.1	5.65
b	5.9	6.5	5.7
b	5.2	6.8	5.4
b	6.4	7.1	5.95
b	5.4	6.1	4.95
b	6.1	6	5.55
b	5.8	6.4	5.55
c	6.1	7.1	5.05
c	6.3	7	5.2
c	6.5	6.2	5.45
c	6.7	6.8	5.55
c	7	7.1	5.85
c	6.5	6.9	4.9
c	7.1	6.7	6
c	6.9	7	4.9
c	6.7	6.9	5.35
c	7.2	7.4	5.85