distribute	reads
0-500	5
500-800	1
800-1000	0
1000-1200	0
1200-1400	0
1400-1600	1
1600-1800	3
1800-2000	0
2000-2200	3
2200-2400	3
2400-2600	0
2600-2800	1
2800-3000	5
>3000	44
