Year % of GNI 2008 0.468225288140369 2009 0.16274227512163 2010 0.291592454340275 2011 0.286749817364306 2012 0.119829153446799 2013 0.0582037251814439 2014 0.0408864447353822 2015 0.0341331132441498 2016 0.038777957541095 2017 0.0411560583605207 2018 0.0448142309887685 2019 0.0342469607147496 2020 0.030771814430118 2021 0.0525272352236925