Year Percent change (Units) 1980 -4.545 1981 -19.841 1982 -14.851 1983 20.930 1984 -4.808 1985 -4.040 1986 -12.632 1987 13.253 1988 -8.309 1989 -1.332 1990 10.085 1991 -10.139 1992 13.575 1993 14.881 1994 2.791 1995 10.359 1996 7.950 1997 27.032 1998 3.101 1999 2.872 2000 13.155 2001 -1.436 2002 4.425 2003 3.136 2004 2.044 2005 3.137 2006 7.747 2007 2.388 2008 1.145 2009 -10.408 2010 13.251 2011 6.910 2012 0.638 2013 6.282 2014 2.040 2015 3.893 2016 0.952 2017 3.358 2018 1.181 2019 8.159 2020 -23.674 2021 27.328 2022 10.739 2023 4.573 2024 2.707 2025 2.309 2026 2.349 2027 2.773 2028 3.194 2029 3.195