Year Percent change (Units) 1980 0.000 1981 -5.104 1982 8.023 1983 19.674 1984 38.975 1985 -9.048 1986 -27.784 1987 8.431 1988 1.932 1989 -9.295 1990 5.538 1991 5.261 1992 -1.910 1993 -1.201 1994 -23.938 1995 125.542 1996 -18.317 1997 11.595 1998 8.344 1999 2.125 2000 5.394 2001 -4.071 2002 1.466 2003 115.928 2004 198.090 2005 33.570 2006 -4.665 2007 -3.799 2008 -9.179 2009 -0.068 2010 -5.488 2011 -3.052 2012 -8.086 2013 -13.573 2014 5.648 2015 35.821 2016 -14.576 2017 -11.546 2018 12.141 2019 12.518 2020 2.117 2021 -8.334 2022 6.504 2023 10.744 2024 -1.241 2025 4.704 2026 0.469 2027 -0.527 2028 -0.640 2029 -0.669