distribute	reads
0-500	35
500-800	1
800-1000	1
1000-1200	1
1200-1400	3
1400-1600	1
1600-1800	3
1800-2000	4
2000-2200	6
2200-2400	5
2400-2600	7
2600-2800	8
2800-3000	7
>3000	144
