Year Percent change 1981 15.353 1982 0.934 1983 -30.968 1984 24.584 1985 -8.531 1986 63.442 1987 83.915 1988 15.381 1989 -35.438 1990 11.646 1991 66.153 1992 -56.506 1993 33.039 1994 36.455 1995 -45.982 1996 149.574 1997 -33.231 1998 24.523 1999 18.37 2000 -35.799 2001 -38.479 2002 72.507 2003 -3.648 2004 -15.317 2005 107.519 2006 131.122 2007 40.95 2008 20.231 2009 -10.247 2010 29.52 2011 -19.383 2012 23.81 2013 -17.663 2014 -5.643 2015 -15.453 2016 -16.286 2017 1.083 2018 -20.482 2019 -18.052 2020 -7.256 2021 -9.851 2022 53.411 2023 -37.019 2024 1.798