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