I know loads of stuff...
And if I don't know it, then I learn it...
If I need to...

Comparitive percentages do not prove the non-existence of anything.

If you place a pea in the center of the universe, then have the ability to see the universe in it's entirety, then the chances are that you will not be able to see the pea (by comparitive scale). Doesn't mean that the pea doesn't exist.
It just means that you are unable to view the pea within the same scalability.

Now, on the other hand.
If we are to measure our intelligence based upon the percentage of other intelligent lifeforms within our universe, then (based upon our awareness of other intelligent lifeforms) you could say that we know everything that there is to know.

So,there ya go!
lol