Year Percent change (Units) 1980 -12.164 1981 -3.000 1982 3.400 1983 2.800 1984 -1.700 1985 -2.000 1986 3.300 1987 4.000 1988 -5.400 1989 -7.500 1990 -15.310 1991 3.802 1992 2.271 1993 0.914 1994 0.984 1995 1.359 1996 0.969 1997 1.077 1998 1.197 1999 1.369 2000 -5.980 2001 5.211 2002 8.060 2003 -26.017 2004 23.261 2005 -7.671 2006 4.610 2007 5.747 2008 -19.224 2009 14.463 2010 3.687 2011 -18.991 2012 43.662 2013 41.138 2014 8.354 2015 15.083 2016 0.460 2017 10.253 2018 2.335 2019 -1.821 2020 4.609 2021 7.753 2022 4.297 2023 7.735 2024 6.961 2025 5.779 2026 5.891 2027 5.742 2028 5.001 2029 2.900