Year US Dollars 1961 819999.99285 1962 5250000 1963 83790000.91553 1964 88470001.2207 1965 101190002.44141 1966 60650001.52588 1967 35569999.69482 1968 28200000.76294 1969 51419998.16895 1970 35689998.62671 1971 25030000.68665 1972 16840000.15259 1973 10090000.15259 1974 14630000.11444 1975 16639999.38965 1976 14810000.41962 1977 6929999.82834 1978 9579999.92371 1979 8930000.30518 1980 8750000 1981 -5849999.90463 1982 12100000.38147 1983 15300000.19073 1984 13760000.22888 1985 21149999.61853 1986 42409999.84741 1987 62299999.23706 1988 11010000.22888 1989 7969999.79019 1990 25930000.30518 1991 -3000000 1992 8760000.22888 1993 2190000.05722 1994 28440000.53406 1995 30770000.45776 1996 19559999.46594 1997 47360000.61035 1998 20780000.68665 1999 38950000.76294 2000 -4590000.15259 2001 -11760000.22888 2002 -16200000.76294 2003 -4510000.22888 2004 -1649999.97616 2005 -2809999.94278 2006 13430000.30518 2007 20120000.83923 2008 8539999.96185 2009 6630000.11444 2010 4449999.80927