Year Percent of GDP (Units) 2004 23.861 2005 21.319 2006 18.996 2007 19.659 2008 19.815 2009 19.634 2010 17.322 2011 17.036 2012 21.544 2013 20.109 2014 23.897 2015 25.656 2016 20.835 2017 20.299 2018 18.990 2019 17.825 2020 18.532 2021 20.780 2022 28.013 2023 24.840 2024 26.053 2025 25.464 2026 24.468 2027 23.655 2028 23.461 2029 23.532