Year Percent change 1981 -0.992 1982 -36.205 1983 -27.134 1984 59.084 1985 -13.886 1986 -3.858 1987 53.256 1988 32.73 1989 -32.525 1990 73.048 1991 -0.628 1992 -25.01 1993 37.199 1994 -49.648 1995 30.183 1996 3.743 1997 -11.047 1998 118.564 1999 -31.21 2000 -29.743 2001 12.023 2002 45.82 2003 35.042 2004 114.455 2005 15.696 2006 37.649 2007 6.778 2008 1.484 2009 87.791 2010 137.952 2011 51.222 2012 3.259 2013 50.235 2014 16.219 2015 -14.867 2016 38.896 2017 13.593 2018 19.717 2019 14.679 2020 6.758 2021 7.676 2022 0.571 2023 1.095 2024 0.57