distribute	reads
0-500	835
500-800	2475
800-1000	2016
1000-1200	2392
1200-1400	2698
1400-1600	2726
1600-1800	2774
1800-2000	2644
2000-2200	2601
2200-2400	2678
2400-2600	2473
2600-2800	2352
2800-3000	2234
>3000	28854
