distribute	reads
0-500	27
500-800	15
800-1000	4
1000-1200	9
1200-1400	1
1400-1600	2
1600-1800	2
1800-2000	0
2000-2200	1
2200-2400	0
2400-2600	1
2600-2800	2
2800-3000	0
>3000	5
