Year Percent Change 1971-01-01 12.859869287981100 1972-01-01 1.775761253324610 1973-01-01 6.843946579571830 1974-01-01 19.614871598948200 1975-01-01 29.881769845713100 1976-01-01 8.579868997967280 1977-01-01 15.375066322181500 1978-01-01 9.778094927339760 1979-01-01 11.487227568121600 1980-01-01 12.046826220658100 1981-01-01 20.089649441798800 1982-01-01 16.806976306757100 1983-01-01 12.454572982285300 1984-01-01 7.023688881722600 1985-01-01 7.063473142704280 1986-01-01 5.413830106738950 1987-01-01 3.934529168844380 1988-01-01 2.435597345330450 1989-01-01 6.240189805403740 1990-01-01 7.999051237417400 1991-01-01 8.304822007285670 1992-01-01 2.672342804586090 1993-01-01 2.610987405803470 1994-01-01 -2.700425336410320 1995-01-01 1.095736549278700 1996-01-01 4.445000926694910 1997-01-01 2.109103580642900 1998-01-01 -0.616630630350681 1999-01-01 0.927519899246414 2000-01-01 -1.680375520757920 2001-01-01 2.682078563471800 2002-01-01 3.340987775192810 2003-01-01 5.680447490768510 2004-01-01 1.520948914915090 2005-01-01 1.554982889502840 2006-01-01 0.920581584939528 2007-01-01 2.206679883175280 2008-01-01 6.172286415313520 2009-01-01 4.460595787666110 2010-01-01 -0.691349413987376