Year Percent change (Units) 1980 12.020 1981 8.154 1982 15.874 1983 10.793 1984 6.517 1985 7.695 1986 8.616 1987 14.890 1988 23.420 1989 4.665 1990 8.787 1991 6.237 1992 -0.208 1993 4.027 1994 -0.786 1995 8.453 1996 2.466 1997 7.106 1998 -1.622 1999 8.035 2000 4.271 2001 2.348 2002 7.434 2003 5.388 2004 1.397 2005 4.972 2006 6.034 2007 5.793 2008 3.252 2009 -14.144 2010 10.122 2011 6.839 2012 -0.171 2013 11.103 2014 5.697 2015 -4.851 2016 7.202 2017 4.113 2018 4.190 2019 3.033 2020 -8.726 2021 11.867 2022 5.782 2023 3.245 2024 3.574 2025 4.593 2026 4.011 2027 3.992 2028 4.023 2029 3.979