Year	current US$
1977	11335898.4
1978	14823457.72
1979	10511388.78
1980	19609090.81
1981	15783966.06
1982	17714208.6
1983	16739881.520000001
1984	15264671.33
1985	15051318.17
1986	24230022.43
1987	28944896.7
1988	33013458.25
1989	31184141.16
1990	35987025.9889842
1991	35199421.5311098
1992	34591173.4856788
1993	35968735.7629801
1994	27377290.0678529