Year Percent change (Units) 2003 1.337 2004 1.429 2005 1.687 2006 2.095 2007 2.475 2008 4.096 2009 2.417 2010 2.413 2011 2.179 2012 2.827 2013 1.604 2014 1.113 2015 0.146 2016 0.644 2017 1.014 2018 1.163 2019 0.473 2020 -0.133 2021 2.083 2022 5.304 2023 6.079 2024 2.264 2025 2.000 2026 2.000 2027 2.000 2028 2.000 2029 2.000