Looking for historical data

Does anyone know of any repository of snapshots of the global routing
tables? I am specifically interested in tracking back to the first
announcements of individual prefixes.

Please respond off-list.

Thanks.

--
Yours,
J.A. Terranson
sysadmin@mfn.org

  The earliest data I have is from late ARPAnet, early NSFnet
  days. (circa 1986-1990) Individual prefixes were in the
  system at that time.

--bill