distance/mm	density/cm^-3
14	7550951000000.0
16	5274477000000.0
18	3644963000000.0
20	2595032000000.0
22	1903118000000.0
24	1364262000000.0
26	1050436000000.0
28	776906800000.0
30	599664100000.0
32	483575500000.0
34	382967700000.0
36	313037800000.0
38	272026100000.0
40	238372600000.0
42	224160100000.0
44	181338300000.0