distribute	reads
0-500	105
500-800	42
800-1000	10
1000-1200	10
1200-1400	8
1400-1600	5
1600-1800	5
1800-2000	2
2000-2200	1
2200-2400	4
2400-2600	1
2600-2800	1
2800-3000	5
>3000	10
