Year Percent change 1980 16.228 1981 3.03 1982 10.28 1983 38.073 1984 25.801 1985 35.424 1986 -15.231 1987 -4.881 1988 10.325 1989 0.602 1990 8.101 1991 11.617 1992 -2.379 1993 -0.605 1994 -4.906 1995 20.417 1996 -10.431 1997 12.505 1998 6.381 1999 5.169 2000 -0.642 2001 25.87 2002 -5.145 2003 16.896 2004 38.054 2005 7.342 2006 15.013 2007 3.237 2008 24.444 2009 -11.993 2010 16.343 2011 8.316 2012 7.544 2013 1.993 2014 12.561 2015 49.864 2016 13.336 2017 4.296 2018 4.452 2019 4.734 2020 4.663 2021 4.575 2022 4.733 2023 4.937 2024 4.206