1.0 and 0.1

I know the male/female meaning of this, but what does this mean 0.0.1

Probably a stupid question, but I was just wondering.

Lots of other people have asked the same question. It can't be stupid if it stumps so many people.

1.2.3 =
1 male
2 females
3 unknown sex

0.0.1 means number of males. Number of females. Number of unknown gender