distribute	reads
0-500	0
500-800	9
800-1000	1
1000-1200	3
1200-1400	1
1400-1600	1
1600-1800	0
1800-2000	1
2000-2200	0
2200-2400	1
2400-2600	0
2600-2800	0
2800-3000	0
>3000	2
