distribute	reads
0-500	1833
500-800	8
800-1000	10
1000-1200	1
1200-1400	2
1400-1600	1
1600-1800	0
1800-2000	0
2000-2200	1
2200-2400	1
2400-2600	0
2600-2800	0
2800-3000	1
>3000	0
