distribute	reads
0-500	15049
500-800	22752
800-1000	9132
1000-1200	6722
1200-1400	5659
1400-1600	4645
1600-1800	3861
1800-2000	3441
2000-2200	3054
2200-2400	2677
2400-2600	2466
2600-2800	2198
2800-3000	1989
>3000	27782
