distribute	reads
0-500	55605
500-800	43146
800-1000	26585
1000-1200	24751
1200-1400	22716
1400-1600	21675
1600-1800	19129
1800-2000	17861
2000-2200	16278
2200-2400	15112
2400-2600	14061
2600-2800	13086
2800-3000	11668
>3000	143901
