distribute	reads
0-500	2923
500-800	2331
800-1000	2511
1000-1200	4063
1200-1400	6359
1400-1600	8866
1600-1800	11422
1800-2000	13348
2000-2200	14575
2200-2400	14728
2400-2600	13749
2600-2800	12001
2800-3000	10111
>3000	27013
