Year Percent change 1980 12.199 1981 5.2 1982 2.4 1983 -22.6 1984 16.9 1985 -14.1 1986 36.3 1987 15 1988 11.9 1989 -14.2 1990 43.1 1991 4.2 1992 4.071 1993 31.644 1994 26.7 1995 11.413 1996 -14.29 1997 -8.262 1998 10.464 1999 -14.957 2000 -7.882 2001 -13.924 2002 11.241 2003 9.864 2004 5.766 2005 -4.939 2006 -5.026 2007 11.714 2008 10.933 2009 -15.804 2010 31.039 2011 19.29 2012 -8.899 2013 12.047 2014 3.94 2015 0.239 2016 -0.378 2017 12.918 2018 4.857 2019 4.019 2020 3.929 2021 3.719 2022 3.693 2023 3.746 2024 3.749