distribute	reads
0-500	70991
500-800	7106
800-1000	647
1000-1200	190
1200-1400	75
1400-1600	47
1600-1800	16
1800-2000	5
2000-2200	7
2200-2400	2
2400-2600	2
2600-2800	2
2800-3000	1
>3000	2
