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