distribute	reads
0-500	7
500-800	10
800-1000	2
1000-1200	3
1200-1400	0
1400-1600	2
1600-1800	1
1800-2000	3
2000-2200	6
2200-2400	7
2400-2600	5
2600-2800	10
2800-3000	10
>3000	319
