Letter Rate 29¢ Package Rate 29¢ Postcard Rate 19¢ Effective 2/3/1991 Great Britain 6/21/1993 Andrew Wiles Proves Last Theorem of Pierre de Fermat Andrew Wiles proved the last theorem of French mathematician Pierre de Fermat. He presented his proof to the public at a conference in Cambridge. A flaw was later discovered and the final proof was presented in May 1995. American President Bill Clinton (1/20/1993-1/20/2001) Argentine President Carlos Menem (7/8/1989-12/10/1999) Australian Prime Minister Paul Keating (12/20/1991-3/11/1996) Austrian President Thomas Klestil (7/8/1992-7/6/2004) Bahamian Prime Minister Hubert Ingraham (8/21/1992-5/3/2002) Belgian Prime Minister Jean-Luc Dehaene (3/7/1992-7/12/1999) Brazilian President Itamar Franco (10/2/1992-12/31/1994) British Prime Minister John Major (11/28/1990-5/2/1997) Canadian Prime Minister Brian Mulroney (9/17/1984-6/24/1993) German President Richard von Weizsäcker (7/1/1984-6/30/1994) Japanese Prime Minister Kiichi Miyazawa (11/5/1991-8/9/1993)