Year Percent change (Units) 1980 10.183 1981 12.462 1982 10.803 1983 5.816 1984 4.339 1985 3.951 1986 4.174 1987 4.365 1988 4.031 1989 4.984 1990 4.780 1991 5.626 1992 1.490 1993 1.865 1994 0.166 1995 2.149 1996 1.571 1997 1.621 1998 0.996 1999 1.735 2000 2.719 2001 2.525 2002 2.258 2003 2.759 2004 1.857 2005 2.214 2006 2.002 2007 2.138 2008 2.370 2009 0.299 2010 1.777 2011 2.912 2012 1.516 2013 0.938 2014 1.907 2015 1.125 2016 1.429 2017 1.597 2018 2.268 2019 1.949 2020 0.717 2021 3.395 2022 6.803 2023 3.879 2024 2.606 2025 1.854 2026 1.894 2027 1.879 2028 1.917 2029 1.987