distribute	reads
0-500	361
500-800	1056
800-1000	765
1000-1200	999
1200-1400	1266
1400-1600	1469
1600-1800	1731
1800-2000	1829
2000-2200	1963
2200-2400	1908
2400-2600	2088
2600-2800	2105
2800-3000	2160
>3000	44766
