distribute	reads
0-500	0
500-800	2
800-1000	1
1000-1200	0
1200-1400	2
1400-1600	4
1600-1800	2
1800-2000	9
2000-2200	7
2200-2400	7
2400-2600	19
2600-2800	33
2800-3000	35
>3000	579
