distribute	reads
0-500	0
500-800	332
800-1000	58
1000-1200	20
1200-1400	12
1400-1600	6
1600-1800	1
1800-2000	3
2000-2200	1
2200-2400	2
2400-2600	0
2600-2800	0
2800-3000	0
>3000	8
