distribute	reads
0-500	37942
500-800	18708
800-1000	9680
1000-1200	8810
1200-1400	7643
1400-1600	6815
1600-1800	6160
1800-2000	5619
2000-2200	5229
2200-2400	4838
2400-2600	4430
2600-2800	4122
2800-3000	3786
>3000	71916
