distribute	reads
0-500	0
500-800	46
800-1000	9
1000-1200	4
1200-1400	2
1400-1600	0
1600-1800	3
1800-2000	0
2000-2200	0
2200-2400	0
2400-2600	0
2600-2800	0
2800-3000	0
>3000	1
