Year Percent of GDP (Units) 1999 46.017 2000 47.549 2001 39.206 2002 41.141 2003 42.571 2004 41.193 2005 44.109 2006 46.432 2007 42.800 2008 40.509 2009 38.343 2010 34.630 2011 37.042 2012 38.034 2013 39.326 2014 40.429 2015 32.992 2016 34.825 2017 33.529 2018 30.560 2019 28.328 2020 25.671 2021 29.031 2022 28.725 2023 28.684 2024 28.724 2025 28.573 2026 27.960 2027 28.334 2028 28.308 2029 28.189