distribute	reads
0-500	9
500-800	4
800-1000	1
1000-1200	0
1200-1400	2
1400-1600	0
1600-1800	3
1800-2000	4
2000-2200	3
2200-2400	3
2400-2600	4
2600-2800	9
2800-3000	16
>3000	110
