distribute	reads
0-500	76908
500-800	58314
800-1000	35241
1000-1200	32173
1200-1400	29440
1400-1600	27551
1600-1800	24230
1800-2000	22137
2000-2200	20273
2200-2400	18605
2400-2600	17131
2600-2800	15881
2800-3000	14117
>3000	172415
