Year % of GNI 1977 32.35302179522316 1978 26.220286748163307 1981 23.02851695094507 1982 24.304620815397517 1983 25.678856283261197 1984 23.55783663772594 1985 21.124239020355656 1986 16.834684631338426 1987 20.298221684379087 1988 16.51410229651292 1989 21.122417478592507 1991 30.941300555357586 1996 30.557807023317608 1998 25.105471185872336 2014 26.05712373637749 2015 19.600956675259468 2018 26.802087598637165 2019 25.093664943232305 2020 16.018500943284167 2021 20.14089818996905