distribute	reads
0-500	169461
500-800	6560
800-1000	529
1000-1200	149
1200-1400	37
1400-1600	14
1600-1800	10
1800-2000	1
2000-2200	1
2200-2400	0
2400-2600	0
2600-2800	0
2800-3000	0
>3000	1
