distribute	reads
0-500	497817
500-800	35629
800-1000	3738
1000-1200	1173
1200-1400	317
1400-1600	100
1600-1800	45
1800-2000	15
2000-2200	5
2200-2400	3
2400-2600	5
2600-2800	1
2800-3000	2
>3000	9
