distribute	reads
0-500	37100
500-800	24014
800-1000	14381
1000-1200	13587
1200-1400	12357
1400-1600	11537
1600-1800	10634
1800-2000	9878
2000-2200	9321
2200-2400	8626
2400-2600	8176
2600-2800	7691
2800-3000	7016
>3000	129200
