If they pay part of the mortgage and utilities and taxes 0.1% is actually quite a bit.
So the most common spider inside is nothing to really be afraid about, mostly they're so tiny they'll be the size of ants. I probably wouldn't even really notice 10 of them.
Now if you would've said the largest spider to frequent your house I would say 0. Get those big ass hairy longleg fast fuckers as far away from me as possible. Eratigena atrica is what they call it.