Year Percent change (Units) 2004 1.087 2005 1.900 2006 2.007 2007 12.319 2008 3.155 2009 1.964 2010 2.991 2011 2.000 2012 2.531 2013 1.458 2014 0.494 2015 0.232 2016 0.833 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