Year % of GNI 1977 32.01883682325795 1978 25.69286243148635 1979 28.502515441085855 1980 26.75116523308295 1989 20.713107264766567 1991 25.961826265041026 1993 26.68675324590423 1994 26.58976429632967 1995 26.815111488361815 1996 28.81559534141833 1997 25.59474661277386 1998 24.2766446792525 1999 27.05554701211866 2000 28.322314160778678 2005 37.09348706106806 2006 38.88084677464889 2008 40.02307667370584 2013 28.723052069518786 2014 25.40809122894454 2015 18.91948080856645 2016 18.66698076599672 2018 27.452218402378836 2019 25.107473788553882 2020 19.17376058812793 2021 24.504551384535052