Year % of GNI 2005 16.41303983181879 2006 17.802331623157947 2007 18.607371977846825 2008 17.454662246772752 2009 16.454094595190462 2010 17.28893544265924 2014 23.235680015603588 2015 21.74937007986486 2016 22.567503283046946 2017 24.64832715429588 2018 22.922629920350428 2019 22.57344725325902 2020 21.847504039950426 2021 19.30734236395509