distribute	reads
0-500	70
500-800	10
800-1000	3
1000-1200	2
1200-1400	1
1400-1600	0
1600-1800	0
1800-2000	0
2000-2200	0
2200-2400	1
2400-2600	1
2600-2800	0
2800-3000	0
>3000	1
