distribute	reads
0-500	13640
500-800	7963
800-1000	3455
1000-1200	2676
1200-1400	2155
1400-1600	1751
1600-1800	1458
1800-2000	1153
2000-2200	1004
2200-2400	816
2400-2600	750
2600-2800	642
2800-3000	534
>3000	4335
