Year Percent of GDP (Units) 1996 2.173 1997 2.512 1998 2.785 1999 2.147 2000 2.489 2001 4.258 2002 4.173 2003 9.186 2004 8.111 2005 8.280 2006 8.454 2007 8.781 2008 10.067 2009 12.383 2010 15.351 2011 13.692 2012 13.405 2013 11.941 2014 12.935 2015 15.231 2016 13.927 2017 10.360 2018 11.729 2019 13.323 2020 12.556 2021 13.783 2022 17.468 2023 17.371 2024 16.175 2025 15.534 2026 15.481 2027 15.522 2028 15.665 2029 15.726