distribute	reads
0-500	83
500-800	0
800-1000	1
1000-1200	3
1200-1400	0
1400-1600	1
1600-1800	1
1800-2000	2
2000-2200	0
2200-2400	3
2400-2600	3
2600-2800	3
2800-3000	0
>3000	11
