PCB.conc	group
29.7	1
24.5	1
97.7	1
39.1	1
22.6	1
32.4	1
27.7	1
100.1	1
40.1	1
23.3	1
33.5	1
28	1
101.5	1
42.5	1
26.2	1
35.8	1
30.8	1
104	1
41.6	2
43	2
56.9	2
40.9	2
32.7	2
44	2
45.3	2
59	2
41	2
33.7	2
44.9	2
46.3	2
59.9	2
44.2	2
35.5	2
48	2
48.4	2
62.8	2