Year Percent of GDP (Units) 1996 42.537 1997 39.120 1998 39.708 1999 41.667 2000 38.455 2001 37.315 2002 39.866 2003 42.133 2004 38.906 2005 36.841 2006 35.777 2007 35.529 2008 40.605 2009 41.667 2010 40.155 2011 41.167 2012 40.815 2013 44.066 2014 47.093 2015 50.973 2016 55.003 2017 52.521 2018 52.202 2019 51.859 2020 58.505 2021 56.895 2022 54.169 2023 53.095 2024 55.550 2025 55.408 2026 55.421 2027 55.622 2028 55.800 2029 56.058