Year % of GDP 1975 2.786649493154744 1976 2.905670502467524 1977 3.3286029826391466 1978 3.8586026909177242 1979 2.8651806619222224 1980 2.917532730091708 1981 4.321493411814717 1982 3.8933762129605474 1983 3.4841751697498684 1984 4.710854509600446 1985 5.14182449455036 1986 3.7856425107163574 1987 3.492181426680132 1988 3.287336364295762 1989 1.7752780471816088 1990 3.199370092101807