Year Percent Change 1971-01-01 10.795488478360900 1972-01-01 5.972701329109030 1973-01-01 27.926192434375200 1974-01-01 29.615813821283600 1975-01-01 23.683429915016800 1976-01-01 18.092035548633500 1977-01-01 13.835574761132300 1978-01-01 16.723912135934800 1979-01-01 18.416067648318900 1980-01-01 31.797374566838000 1981-01-01 16.859927353125900 1982-01-01 17.420803882139900 1983-01-01 25.880258961655000 1984-01-01 13.271643409418200 1985-01-01 6.404673635291750 1986-01-01 8.399000733206830 1987-01-01 9.686261897972760 1988-01-01 10.358001394518500 1989-01-01 9.207030437398520 1990-01-01 8.026091595262720 1991-01-01 7.881641600021010 1992-01-01 10.202343941313500 1993-01-01 2.004848829871560 1994-01-01 5.346372697639820 1995-01-01 3.982078993088330 1996-01-01 5.471751010211140 1997-01-01 2.917932171512940 1998-01-01 1.602677052488280 1999-01-01 3.586609637725600 2000-01-01 2.797970690871680 2001-01-01 2.358783664133560 2002-01-01 3.529060552738240 2003-01-01 1.987926010842380 2004-01-01 3.848804611879820 2005-01-01 5.776602956179350 2006-01-01 3.494489465269800 2007-01-01 2.495762581164060 2008-01-01 2.496542826634320 2009-01-01 0.668068469481542 2010-01-01 2.307801436297600