Year Percent of GDP (Units) 2004 63.131 2005 61.406 2006 55.575 2007 52.319 2008 53.110 2009 55.903 2010 55.101 2011 57.821 2012 56.846 2013 57.243 2014 52.513 2015 47.809 2016 41.829 2017 35.395 2018 32.649 2019 28.999 2020 41.827 2021 43.729 2022 46.445 2023 47.107 2024 49.282 2025 50.943 2026 52.454 2027 52.605 2028 52.657 2029 52.692