Year Percent change 1980 18.14 1981 13.856 1982 -2.753 1983 14.805 1984 22.1 1985 5.568 1986 15.257 1987 33.509 1988 26.771 1989 10.431 1990 9.514 1991 17.316 1992 19.82 1993 13.614 1994 9.985 1995 11.407 1996 4.569 1997 6.023 1998 -4.568 1999 3.632 2000 18.535 2001 -1.795 2002 8.365 2003 14.862 2004 15.644 2005 12.416 2006 10.236 2007 6.875 2008 3.241 2009 -11.255 2010 18.031 2011 4.631 2012 3.305 2013 8.211 2014 0.84 2015 -1.726 2016 1.558 2017 6.451 2018 3.547 2019 2.101 2020 2.99 2021 3.403 2022 3.52 2023 3.603 2024 3.544