Year Percent of GDP (Units) 2004 21.419 2005 22.913 2006 21.162 2007 22.478 2008 22.208 2009 22.377 2010 22.125 2011 21.327 2012 23.497 2013 22.419 2014 24.796 2015 22.969 2016 23.251 2017 22.080 2018 22.951 2019 22.341 2020 21.586 2021 20.670 2022 22.647 2023 20.801 2024 19.979 2025 19.934 2026 19.934 2027 19.934 2028 19.934 2029 19.934