Year Percent change 1980 1.009 1981 2.961 1982 2.878 1983 -0.124 1984 6.858 1985 1.213 1986 1.81 1987 2.436 1988 0.555 1989 1.498 1990 1.057 1991 -2.168 1992 0.87 1993 4.874 1994 6.673 1995 4.345 1996 3.74 1997 3.016 1998 0.762 1999 4.464 2000 4.123 2001 2.196 2002 5.079 2003 4.603 2004 4.409 2005 2.555 2006 2.748 2007 3.963 2008 -0.408 2009 0.322 2010 2.011 2011 1.866 2012 2.549 2013 2.192 2014 3.135 2015 4.003 2016 4.187 2017 2.559 2018 2.991 2019 2.519 2020 2.924 2021 2.845 2022 2.52 2023 2.487 2024 2.532