distribute	reads
0-500	17
500-800	4
800-1000	1
1000-1200	0
1200-1400	2
1400-1600	1
1600-1800	1
1800-2000	0
2000-2200	1
2200-2400	0
2400-2600	1
2600-2800	0
2800-3000	0
>3000	7
