Year % of GNI 1996 33.221891025981314 1997 33.28459724846053 1998 32.71852060253346 1999 31.141838427416943 2000 31.344902148559996 2001 30.630465057165445 2002 30.373952426488838 2003 31.25698629269188 2004 32.50189171409796 2005 33.01808382255877 2006 34.393461932047785 2007 35.974725335066694 2008 36.354349631941254 2009 35.283028696554794 2010 36.686425999493146 2011 36.36809810660716 2012 36.18168663887329 2013 36.79755004739255 2014 37.521211961195554 2015 37.54027578316304 2016 36.958616792478345 2017 37.70102996354821 2018 37.651461880245286 2019 37.16579459253617 2020 37.397525327685514 2021 38.750299408693316