fraction  mass  Mn_x10^-4  Mw_x10^-4
6    2 109   111
7    8  90.8  92.5
8   20  76.7  78.0
9   42  62.3  63.5
10  64  51.5  52.5
11  84  41.7  42.5
12 102  34.7  35.4
13 110  28.7  29.3
14 110  23.3  23.8
15  96  18.9  19.4
16  86  15.9  16.3
17  68  13.0  13.3
18  54  11.0  11.2
19  42   9.14  9.35
20  30   7.52  7.68
21  28   6.16  6.28
22  18   5.12  5.22
23  12   4.09  4.18
24   8   3.33  3.40
25   6   2.63  2.69
26   5   2.01  2.06
27   4   1.52  1.56
28   3   1.13  1.16
29   2   0.83  0.85
30   1   0.59  0.61