Year Percent of GDP 1997 19.937 1998 19.17 1999 17.14 2000 16.652 2001 16.778 2002 17.224 2003 15.777 2004 17.237 2005 17.377 2006 18.56 2007 19.979 2008 19.877 2009 18.5 2010 18.147 2011 14.248 2012 19.166 2013 19.679 2014 18.862 2015 19.988 2016 19.954 2017 20.365 2018 19.707 2019 20.047 2020 20.185 2021 20.344 2022 20.341 2023 20.513 2024 20.456