group	expression
A	0.1
A	0.3
A	0.4
A	0.7
A	1.2
A	1.6
A	1.7
A	1.8
A	1.9
A	2
B	0.2
B	0.5
B	0.6
B	0.8
B	0.9
B	1
B	1.1
B	1.3
B	1.4
B	1.5