distribute	reads
0-500	41
500-800	5
800-1000	2
1000-1200	1
1200-1400	1
1400-1600	0
1600-1800	0
1800-2000	0
2000-2200	0
2200-2400	0
2400-2600	2
2600-2800	0
2800-3000	1
>3000	6
