how large can a CRL list get?

my IE browser uses certificates to authenticate web servers i visit.

this got me thinking

so i assume that every now and then the browser needs to update its CRL

how large does this CRL file typically be? is it the same for all the
users of IE?
does IE download a CRL from each of the default CAs which come with IE?

does a CRL include revoked certs whose expiry date has passed?

thanks,
B