Year Percent change 1980 1.594 1981 1.994 1982 2.236 1983 -1.511 1984 -18.323 1985 -12.774 1986 3.488 1987 17.604 1988 12.893 1989 21.902 1990 6.039 1991 -3.43 1992 7.773 1993 12.597 1994 15.609 1995 11.558 1996 12.334 1997 7.316 1998 -11.194 1999 -14.927 2000 22.464 2001 -0.491 2002 3.403 2003 10.107 2004 6.577 2005 4.471 2006 5.597 2007 2.905 2008 9.762 2009 -9.87 2010 17.51 2011 -0.495 2012 10.184 2013 -3.284 2014 12.245 2015 4.758 2016 24.56 2017 24.004 2018 12.134 2019 14.626 2020 13.983 2021 7.128 2022 7.078 2023 7.326 2024 7.486