distribute	reads
0-500	1462
500-800	3793
800-1000	3493
1000-1200	4751
1200-1400	6611
1400-1600	7562
1600-1800	7536
1800-2000	7084
2000-2200	6670
2200-2400	6158
2400-2600	5611
2600-2800	5327
2800-3000	5034
>3000	44645
