distribute	reads
0-500	0
500-800	14
800-1000	4
1000-1200	3
1200-1400	2
1400-1600	2
1600-1800	2
1800-2000	2
2000-2200	0
2200-2400	1
2400-2600	1
2600-2800	0
2800-3000	0
>3000	0
