Year Percent change (Units) 2001 1.531 2002 5.051 2003 2.914 2004 2.369 2005 3.221 2006 4.190 2007 2.285 2008 10.443 2009 -0.283 2010 -1.853 2011 0.500 2012 1.415 2013 2.020 2014 1.124 2015 3.140 2016 3.492 2017 4.087 2018 2.160 2019 3.492 2020 1.859 2021 6.217 2022 11.540 2023 6.205 2024 4.131 2025 3.559 2026 3.247 2027 2.959 2028 2.840 2029 2.804