Year	US Dollars
1970	-20619333.14567
1971	-23682842.85545
1972	-27428699.99804
1973	-30983050.84746
1974	-33810855.26316
1975	-22627408.83763
1976	-25469880.78363
1977	-26785816.04766
1978	-34737319.88473
1979	-40604249.75069
1980	-32260389.08848
1981	-37948636.36364
1982	-55359312.11726
1983	-42930229.98187
1984	-52456093.07173
1985	-68981290.62608
1986	-34639706.6701
1987	-47959971.0799
1988	-63690186.89628
1989	-79499781.78539
1990	-66110099.87236
1991	-71510010.42883
1992	-102314940.81121
1993	-56489982.9923
1994	-42069872.73407
1995	-59621512.58582
1996	-57630141.83785
1997	-50665828.80651
1998	-44180153.19218
1999	-40300058.90865
2000	-42057804.4522
2001	-22078922.18485
2002	-22946902.11398
2003	-28164059.79144
2004	-42092163.16653
2005	-52922631.71934
2006	-87307363.44023
2007	-95766533.37974
2008	-111893488.08511
2009	-135373400.28713
2010	-172833735.74305
2011	-57970541.37577
2012	-101190683.84065
2013	-79124564.81257
2014	-117763862.34236
2015	-49199297.6577
2016	-56506638.5254
2017	-57010206.61431