Year % of GNI 1999 36.04612462167012 2000 35.87311104792856 2001 34.199764781668534 2002 32.46393897897368 2003 29.501508014213517 2004 36.73424915345309 2005 39.61880672951135 2006 36.096712739423126 2007 43.34861024602373 2008 38.17317193462724 2009 18.509932171291958 2010 26.39112661680466 2011 26.839044606004848 2012 33.12979120324648 2013 31.21037861194591 2014 33.21231456596528 2015 27.67079808242799 2016 29.536867675394486 2017 30.298023200804973 2018 28.583433595429984 2019 26.28421680808395 2020 30.66230340485898 2021 29.624497589966882 2022 27.50630096411443 2023 24.740547514018175