distribute	reads
0-500	121
500-800	40
800-1000	0
1000-1200	0
1200-1400	1
1400-1600	3
1600-1800	5
1800-2000	8
2000-2200	9
2200-2400	12
2400-2600	8
2600-2800	6
2800-3000	5
>3000	4
