distribute	reads
0-500	8488
500-800	20809
800-1000	15873
1000-1200	18461
1200-1400	18800
1400-1600	16672
1600-1800	14167
1800-2000	11709
2000-2200	9678
2200-2400	7920
2400-2600	6500
2600-2800	5285
2800-3000	4167
>3000	14261
