distribute	reads
0-500	145823
500-800	6649
800-1000	579
1000-1200	152
1200-1400	56
1400-1600	14
1600-1800	3
1800-2000	1
2000-2200	0
2200-2400	1
2400-2600	0
2600-2800	0
2800-3000	0
>3000	1
