Year Percent change (Units) 1996 8.759 1997 8.596 1998 10.698 1999 2.135 2000 3.775 2001 4.663 2002 1.903 2003 0.119 2004 2.760 2005 1.857 2006 2.534 2007 2.853 2008 6.359 2009 1.019 2010 1.473 2011 1.917 2012 3.288 2013 1.438 2014 0.344 2015 0.309 2016 0.684 2017 2.451 2018 2.149 2019 2.848 2020 3.161 2021 3.840 2022 15.100 2023 10.661 2024 2.138 2025 2.025 2026 2.000 2027 2.000 2028 2.000 2029 2.000