Year Percent change (Units) 1980 6.838 1981 8.460 1982 5.700 1983 2.696 1984 1.142 1985 1.129 1986 1.897 1987 4.491 1988 4.822 1989 3.300 1990 3.012 1991 4.511 1992 2.878 1993 -0.699 1994 1.408 1995 3.009 1996 6.966 1997 2.731 1998 2.863 1999 2.187 2000 1.556 2001 1.724 2002 0.240 2003 2.260 2004 6.814 2005 8.966 2006 11.709 2007 13.739 2008 15.068 2009 -4.870 2010 -2.389 2011 1.981 2012 1.829 2013 3.143 2014 4.244 2015 0.939 2016 2.689 2017 0.604 2018 0.100 2019 -0.900 2020 -2.523 2021 2.277 2022 4.960 2023 3.086 2024 2.580 2025 2.382 2026 2.223 2027 2.044 2028 2.018 2029 1.964