Year Percent change (Units) 2002 -2.638 2003 -1.562 2004 0.981 2005 4.396 2006 5.150 2007 5.571 2008 8.611 2009 1.169 2010 2.809 2011 5.806 2012 6.107 2013 5.501 2014 6.048 2015 4.561 2016 2.369 2017 1.228 2018 3.004 2019 2.752 2020 0.811 2021 0.027 2022 1.045 2023 0.936 2024 1.700 2025 2.250 2026 2.400 2027 2.500 2028 2.500 2029 2.500