Year Percent of GDP (Units) 2001 32.257 2002 29.877 2003 29.266 2004 29.476 2005 30.853 2006 31.656 2007 31.649 2008 30.532 2009 28.222 2010 28.770 2011 29.080 2012 29.109 2013 31.222 2014 31.298 2015 31.501 2016 30.977 2017 30.400 2018 30.014 2019 30.037 2020 30.691 2021 31.693 2022 32.715 2023 29.276 2024 30.512 2025 30.401 2026 31.025 2027 31.212 2028 31.153 2029 31.296