Year Percent change (Units) 1980 22.100 1981 1.779 1982 11.217 1983 -23.348 1984 -14.085 1985 -19.046 1986 28.654 1987 7.591 1988 11.508 1989 5.349 1990 4.688 1991 1.925 1992 -4.188 1993 14.576 1994 3.922 1995 -33.196 1996 3.490 1997 2.895 1998 16.686 1999 47.711 2000 -9.417 2001 -3.792 2002 50.442 2003 4.741 2004 0.891 2005 10.153 2006 10.723 2007 -3.031 2008 10.130 2009 5.504 2010 -6.922 2011 36.165 2012 47.812 2013 18.773 2014 -1.469 2015 1.864 2016 -33.723 2017 5.679 2018 11.608 2019 10.643 2020 -8.888 2021 8.986 2022 48.909 2023 -27.679 2024 23.830 2025 -0.045 2026 4.069 2027 0.667 2028 -0.719 2029 -0.761