I was going through some old mail archives and I found this:

Date: Tue, 29 Apr 1997 01:02:01 -0500
Subject: Auto Reset of ipfwadm stats
Tue Apr 29 01:02:01 CDT 1997
Stats for yesterday:
IP accounting rules
 pkts bytes dir prot source               destination          ports
  144 28693 i/o all  ppp01.hoopeston.k12.il.us anywhere             n/a
 7336 2332K i/o all  ppp02.hoopeston.k12.il.us anywhere             n/a
    0     0 i/o all  ppp03.hoopeston.k12.il.us anywhere             n/a
    0     0 i/o all  ppp04.hoopeston.k12.il.us anywhere             n/a

That’s just the earliest mail I can find, it was running before April. Hard to believe we’ve had dialup running in Hoopeston for more than 10 years.