distribute	reads
0-500	13575
500-800	4205
800-1000	1837
1000-1200	1584
1200-1400	1324
1400-1600	1129
1600-1800	1042
1800-2000	889
2000-2200	790
2200-2400	728
2400-2600	733
2600-2800	609
2800-3000	599
>3000	11691
