As I said above: you can't
. Squid is a web-proxy, you'll
get http and web-traffic at best. To be able to do what
you're after you'll need to get nufw or something the like
(which gives you a breakdown per individual since it requires
authentication) or you'll have to use iptables ulog and be
content with accounting per IP address.
Re-requesting the same (impossible) thing won't make it
achievable. That's like saying how do I get my BMW to
fly ... ain't happening (at least not w/o serious money,
time and effort - same with squid).