Year % of GNI 1977 32.018836823257956 1978 25.69286243148635 1979 28.502515441085848 1980 26.751165233082943 1989 20.713107264766567 1991 25.961826265041033 1993 26.686753245904235 1994 26.58976429632967 1995 27.101830224512913 1996 29.117356281975194 1997 25.88715828190776 1998 24.52384216042651 1999 27.352500726312165 2000 28.580664234946855 2005 37.541891366622494 2006 39.278564312118256 2008 40.17040038733564 2013 29.01664620268195 2014 25.65958447878879 2015 19.05608266950022 2016 18.813078697351894 2018 27.719496412788775 2019 25.310808682280097 2020 19.327361882627493 2021 24.719674858769032