Year Percent change (Units) 1992 3.300 1993 4.200 1994 2.500 1995 1.500 1996 1.457 1997 1.445 1998 0.130 1999 1.423 2000 2.041 2001 1.375 2002 0.986 2003 1.099 2004 2.174 2005 2.128 2006 1.389 2007 3.082 2008 0.997 2009 0.877 2010 1.848 2011 2.348 2012 2.086 2013 1.328 2014 0.202 2015 0.201 2016 1.707 2017 1.579 2018 1.846 2019 1.336 2020 -0.534 2021 5.428 2022 10.805 2023 2.971 2024 2.222 2025 1.959 2026 1.971 2027 1.974 2028 1.988 2029 2.009