Year Percent Change 1971-01-01 4.871977791615700 1972-01-01 4.161909580535230 1973-01-01 5.769255168125510 1974-01-01 10.472628804784200 1975-01-01 8.514760136293110 1976-01-01 6.372724301389240 1977-01-01 6.661666176581830 1978-01-01 8.077890739248040 1979-01-01 9.694690984392430 1980-01-01 11.091856369047700 1981-01-01 8.251822721312180 1982-01-01 6.379060837979080 1983-01-01 3.830987582779300 1984-01-01 2.768335722137430 1985-01-01 3.371923854392270 1986-01-01 3.349227930095800 1987-01-01 3.154690398174440 1988-01-01 2.814840235269020 1989-01-01 3.639320167936870 1990-01-01 4.812246610582310 1991-01-01 4.266110784806230 1992-01-01 3.025421126618280 1993-01-01 2.694347030004580 1994-01-01 1.241089193910680 1995-01-01 1.326603238327420 1996-01-01 0.725521772930461 1997-01-01 1.051404342784520 1998-01-01 2.133843751360820 1999-01-01 1.266000827099940 2000-01-01 2.370889438318360 2001-01-01 2.258857195324670 2002-01-01 1.562756921774020 2003-01-01 2.343608002452340 2004-01-01 1.676201832354560 2005-01-01 2.503244245985650 2006-01-01 3.088026281565740 2007-01-01 2.788529896820480 2008-01-01 1.588831927586400 2009-01-01 0.149628944896220 2010-01-01 0.144597037237313