Year % of GNI 1990 1.05944879211405 2013 0.462299233481694 2014 0.438215008064801 2015 0.425996055151823 2016 0.430650506834466 2017 0.442850402711213 2018 0.444149402061446 2019 0.436286386451587 2020 0.429279807492103 2021 0.417209367958526