Year % of merchandise exports 1963 31.847360442891983 1967 17.13028548283249 1970 19.80343119872273 1971 17.93015095476178 1972 15.34310857054729 1973 18.40773378466938 1974 20.56990270966304 1975 14.999591049326305 1976 19.228668027791194 1977 19.77495918164901 1978 25.477079882522492 1979 27.269810554593736 1980 29.264267351802697 1981 23.570435920335814 1982 18.197402848979582 1983 22.87762781716949 1984 25.560104659502546