distribute	reads
0-500	3
500-800	0
800-1000	0
1000-1200	1
1200-1400	1
1400-1600	2
1600-1800	2
1800-2000	3
2000-2200	8
2200-2400	14
2400-2600	28
2600-2800	28
2800-3000	60
>3000	684
