distribute	reads
0-500	113594
500-800	4011
800-1000	217
1000-1200	26
1200-1400	8
1400-1600	0
1600-1800	0
1800-2000	1
2000-2200	0
2200-2400	0
2400-2600	0
2600-2800	0
2800-3000	0
>3000	2
