distribute	reads
0-500	32
500-800	2
800-1000	1
1000-1200	0
1200-1400	0
1400-1600	0
1600-1800	2
1800-2000	3
2000-2200	2
2200-2400	5
2400-2600	0
2600-2800	2
2800-3000	2
>3000	38
