Year Percent change 1981 12.508 1982 23.522 1983 9.575 1984 22.776 1985 -13.473 1986 29.567 1987 1.62 1988 6.23 1989 -4.008 1990 -12.999 1991 -1.275 1992 67.418 1993 20.079 1994 -18.766 1995 -10.635 1996 16.204 1997 33.404 1998 -2.823 1999 3.342 2000 3.84 2001 10.509 2002 5.136 2003 12.312 2004 12.947 2005 6.853 2006 5.325 2007 14.265 2008 30.164 2009 -9.59 2010 80.871 2011 27.535 2012 8.031 2013 10.171 2014 44.771 2015 -19.964 2016 3.526 2017 3.691 2018 -2.031 2019 0.393 2020 -1.729 2021 4.747 2022 4.533 2023 11.133 2024 9.42