distribute	reads
0-500	429
500-800	1695
800-1000	1803
1000-1200	2601
1200-1400	2953
1400-1600	3039
1600-1800	3116
1800-2000	3187
2000-2200	3314
2200-2400	3096
2400-2600	3054
2600-2800	3002
2800-3000	2935
>3000	49747
