distribute	reads
0-500	32363
500-800	29886
800-1000	19907
1000-1200	19829
1200-1400	19960
1400-1600	19861
1600-1800	21149
1800-2000	23440
2000-2200	27602
2200-2400	33363
2400-2600	39974
2600-2800	49022
2800-3000	57765
>3000	981438
