distribute	reads
0-500	10063
500-800	33176
800-1000	21100
1000-1200	20558
1200-1400	19141
1400-1600	18501
1600-1800	17361
1800-2000	16364
2000-2200	15779
2200-2400	14784
2400-2600	14440
2600-2800	13593
2800-3000	13040
>3000	379266
