Year Percent of GDP (Units) 1997 18.398 1998 26.826 1999 28.266 2000 26.066 2001 25.848 2002 25.323 2003 24.674 2004 24.992 2005 25.434 2006 25.928 2007 26.130 2008 26.842 2009 26.093 2010 25.867 2011 25.407 2012 24.789 2013 23.977 2014 26.272 2015 26.440 2016 27.642 2017 27.756 2018 27.457 2019 27.209 2020 25.853 2021 27.527 2022 26.787 2023 27.919 2024 27.717 2025 27.435 2026 27.639 2027 27.655 2028 27.706 2029 27.690