Year Percent change 1980 1.272 1981 0.11 1982 -0.788 1983 1.555 1984 2.826 1985 2.192 1986 2.417 1987 1.469 1988 3.736 1989 3.913 1990 5.723 1991 5.011 1992 1.51 1993 -0.984 1994 2.532 1995 1.809 1996 0.863 1997 1.907 1998 1.769 1999 1.84 2000 3.195 2001 1.832 2002 0.027 2003 -0.722 2004 0.698 2005 0.878 2006 3.881 2007 3.365 2008 0.815 2009 -5.56 2010 3.939 2011 3.72 2012 0.691 2013 0.602 2014 2.177 2015 1.484 2016 2.157 2017 2.456 2018 1.452 2019 0.754 2020 1.44 2021 1.503 2022 1.44 2023 1.304 2024 1.156