Year Percent change (Units) 1980 6.656 1981 7.626 1982 8.723 1983 7.663 1984 6.348 1985 4.868 1986 1.296 1987 1.554 1988 1.162 1989 3.105 1990 3.453 1991 3.167 1992 2.260 1993 2.487 1994 2.394 1995 1.265 1996 1.760 1997 1.499 1998 0.901 1999 1.134 2000 2.682 2001 2.438 2002 1.552 2003 1.517 2004 1.857 2005 2.539 2006 2.331 2007 1.819 2008 4.490 2009 -0.004 2010 2.329 2011 3.344 2012 2.621 2013 1.252 2014 0.495 2015 0.623 2016 1.774 2017 2.222 2018 2.309 2019 1.249 2020 0.421 2021 3.210 2022 10.325 2023 2.293 2024 3.623 2025 1.993 2026 1.883 2027 1.910 2028 2.044 2029 2.023