distribute	reads
0-500	0
500-800	83
800-1000	22
1000-1200	11
1200-1400	10
1400-1600	5
1600-1800	2
1800-2000	1
2000-2200	1
2200-2400	1
2400-2600	0
2600-2800	0
2800-3000	1
>3000	3
