distribute	reads
0-500	0
500-800	384
800-1000	64
1000-1200	28
1200-1400	22
1400-1600	14
1600-1800	11
1800-2000	18
2000-2200	12
2200-2400	11
2400-2600	8
2600-2800	7
2800-3000	4
>3000	72
