Year Percent change (Units) 1980 13.728 1981 13.892 1982 9.691 1983 9.292 1984 6.690 1985 4.703 1986 2.121 1987 3.115 1988 3.081 1989 3.563 1990 3.212 1991 3.264 1992 2.010 1993 2.227 1994 1.439 1995 2.107 1996 1.699 1997 1.140 1998 0.236 1999 1.360 2000 1.806 2001 1.496 2002 2.185 2003 2.407 2004 2.243 2005 1.727 2006 1.675 2007 2.787 2008 1.164 2009 0.988 2010 1.988 2011 2.634 2012 1.519 2013 0.839 2014 0.110 2015 0.290 2016 0.829 2017 1.278 2018 1.937 2019 1.670 2020 -0.227 2021 3.371 2022 6.991 2023 4.185 2024 1.829 2025 1.942 2026 1.725 2027 2.011 2028 1.584 2029 1.984