Year Percent change (Units) 1980 4.555 1981 4.540 1982 1.397 1983 2.058 1984 4.347 1985 2.326 1986 2.971 1987 3.302 1988 2.468 1989 2.658 1990 0.751 1991 -1.103 1992 -0.935 1993 -1.829 1994 3.930 1995 3.935 1996 1.579 1997 3.071 1998 4.312 1999 4.247 2000 4.766 2001 1.449 2002 2.197 2003 2.310 2004 4.337 2005 2.859 2006 4.663 2007 3.439 2008 -0.451 2009 -4.340 2010 5.952 2011 3.195 2012 -0.588 2013 1.188 2014 2.658 2015 4.489 2016 2.071 2017 2.568 2018 1.950 2019 1.986 2020 -2.170 2021 6.147 2022 2.663 2023 -0.196 2024 0.215 2025 2.223 2026 2.175 2027 2.195 2028 2.123 2029 2.117