Year Percent change (Units) 1989 5.609 1990 3.951 1991 6.077 1992 4.217 1993 6.109 1994 4.000 1995 4.100 1996 -1.667 1997 2.538 1998 4.726 1999 0.430 2000 1.033 2001 7.643 2002 0.830 2003 1.273 2004 -0.662 2005 -0.633 2006 3.080 2007 0.036 2008 24.237 2009 -1.307 2010 -1.923 2011 -0.828 2012 -3.830 2013 0.832 2014 3.116 2015 0.542 2016 0.839 2017 2.499 2018 -1.134 2019 -0.906 2020 2.769 2021 2.534 2022 16.207 2023 -2.109 2024 4.776 2025 2.500 2026 2.000 2027 1.900 2028 1.800 2029 1.800