distribute	reads
0-500	1
500-800	2
800-1000	0
1000-1200	1
1200-1400	1
1400-1600	5
1600-1800	3
1800-2000	9
2000-2200	15
2200-2400	39
2400-2600	60
2600-2800	90
2800-3000	139
>3000	3024
