density	concentration
0.017	0.04882812
0.018	0.04882812
0.121	0.1953125
0.124	0.1953125
0.206	0.390625
0.215	0.390625
0.377	0.78125
0.374	0.78125
0.614	1.5625
0.609	1.5625
1.019	3.125
1.001	3.125
1.334	6.25
1.364	6.25
1.73	12.5
1.71	12.5