The page is now giving a 404 error (maybe was removed after the traffic spike?). But here's the most recent archive.org mirror: https://web.archive.org/web/2018

The page is now giving a 404 error (maybe was removed after the traffic spike?). But here's the most recent archive.org mirror: https://web.archive.org/web/20180430071524/http://www.columbia.edu/~fdc/postal/ https://web.archive.org/web/20180430071524/http://www.columb...