Year Percent change 1980 0.705 1981 -9.523 1982 20.759 1983 13.518 1984 -7.62 1985 3.649 1986 2.364 1987 2.8 1988 1.702 1989 4.331 1990 5.696 1991 2.163 1992 1.763 1993 3.833 1994 -3.398 1995 3.32 1996 2.906 1997 1.417 1998 6.5 1999 6.399 2000 5.525 2001 5.753 2002 -3.247 2003 6.874 2004 7.046 2005 -1.004 2006 1.115 2007 3.518 2008 5.737 2009 6.47 2010 6.521 2011 -4.322 2012 5.647 2013 4.801 2014 -0.94 2015 5.868 2016 0.406 2017 4.558 2018 6.6 2019 5.395 2020 5.245 2021 5.023 2022 4.816 2023 4.817 2024 4.781