Year Percent change (Units) 1980 10.113 1981 10.816 1982 7.102 1983 8.554 1984 8.792 1985 -0.623 1986 1.343 1987 10.798 1988 11.264 1989 10.159 1990 9.821 1991 6.688 1992 6.640 1993 11.460 1994 11.096 1995 7.175 1996 7.471 1997 8.316 1998 -2.191 1999 5.718 2000 9.038 2001 -1.071 2002 3.923 2003 4.548 2004 9.940 2005 7.366 2006 9.007 2007 9.022 2008 1.863 2009 0.128 2010 14.520 2011 6.215 2012 4.435 2013 4.818 2014 3.936 2015 2.977 2016 3.589 2017 4.513 2018 3.517 2019 1.345 2020 -3.870 2021 9.691 2022 3.838 2023 1.075 2024 2.100 2025 2.300 2026 2.523 2027 2.487 2028 2.483 2029 2.501