September 30, 1976
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March 6, 1980
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June 30, 1984
September 17, 1984
March 31, 1988
February 3, 1990
April 21, 1991
July 12,1996
August 3, 1999
January 15, 2002
June 12, 2003
June 17, 2003
December 12, 2003
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February 6 2006
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