Year Percent of GDP (Units) 2003 37.044 2004 36.585 2005 35.558 2006 35.332 2007 34.989 2008 33.870 2009 33.010 2010 29.623 2011 29.393 2012 29.078 2013 28.344 2014 28.683 2015 28.206 2016 27.720 2017 28.306 2018 29.553 2019 31.951 2020 34.509 2021 35.614 2022 37.863 2023 39.794 2024 41.402 2025 41.757 2026 42.386 2027 42.623 2028 43.035 2029 43.475