distribute	reads
0-500	10344
500-800	15680
800-1000	9028
1000-1200	8321
1200-1400	6873
1400-1600	6181
1600-1800	5561
1800-2000	4893
2000-2200	4347
2200-2400	4054
2400-2600	3714
2600-2800	3379
2800-3000	3140
>3000	40748
