distribute	reads
0-500	0
500-800	44
800-1000	11
1000-1200	4
1200-1400	6
1400-1600	3
1600-1800	2
1800-2000	1
2000-2200	2
2200-2400	0
2400-2600	1
2600-2800	0
2800-3000	1
>3000	3
