distribute	reads
0-500	78761
500-800	47274
800-1000	26057
1000-1200	23588
1200-1400	21063
1400-1600	19069
1600-1800	17184
1800-2000	15808
2000-2200	14589
2200-2400	13228
2400-2600	12258
2600-2800	11611
2800-3000	10907
>3000	163247
