distribute	reads
0-500	16
500-800	16
800-1000	11
1000-1200	7
1200-1400	9
1400-1600	10
1600-1800	14
1800-2000	4
2000-2200	18
2200-2400	27
2400-2600	27
2600-2800	27
2800-3000	42
>3000	2803
