distribute	reads
0-500	26962
500-800	24174
800-1000	12567
1000-1200	10536
1200-1400	8396
1400-1600	6619
1600-1800	5004
1800-2000	3697
2000-2200	2689
2200-2400	1779
2400-2600	1336
2600-2800	931
2800-3000	587
>3000	1254
