Year Percent of GDP (Units) 2002 23.986 2003 23.813 2004 25.909 2005 25.835 2006 27.447 2007 27.689 2008 37.282 2009 32.620 2010 33.128 2011 36.057 2012 31.901 2013 29.998 2014 27.847 2015 30.433 2016 33.522 2017 34.694 2018 36.295 2019 34.558 2020 33.406 2021 35.950 2022 35.307 2023 32.221 2024 31.405 2025 31.970 2026 32.617 2027 33.321 2028 34.098 2029 34.685