And to follow up that quote, while attempting to pique the interest of our gutter police, the Guide continues

Population: None.

It is known that there are an infinite number of worlds, simply
because there is an infinite amount of space for them to be in.
However, not every one of them is inhabited. Therefore, there
must be a finite number of inhabited worlds. Any finite number
divided by infinity is as near to nothing as makes no odds, so
the average population of all the planets in the Universe can be
said to be zero.

Art: None.

The function of art is to hold the mirror up to nature, and there
simply isn't a mirror big enough.

Sex: None.

Well, in fact there is an awful lot of this, largely because of
the total lack of money, trade, banks, art, or anything else that
might keep all the non-existent people of the Universe occupied.
However, it is not worth embarking on a long discussion of it now
because it really is terribly complicated. For further
information see Guide Chapters seven, nine, ten, eleven,
fourteen, sixteen, seventeen, nineteen, twenty-one to eighty-four
inclusive.