Year	US Dollars adjusted for inflation)
1987	17896955795.4981
1988	19532483825.5126
1989	20136290320.8457
1990	20458470967.0987
1991	20357815289.1324
1992	18077739977.2729
1993	17661951956.7725
1994	16743530456.4451
1995	16592838681.2958
1996	16874916939.4794
1997	17752412619.8816
1998	18515766362.5365
1999	19311944316.6708
2000	20045798199.4212
2001	20887721725.4289
2002	21723230593.7918
2003	22635606278.4075
2004	24378547961.2961
2005	26085046319.8044
2006	27989254700.4723
2007	30766111720.2779
2008	33535061775.1937
2009	36251401777.576
2010	39332770928.94259
2011	42597390915.6831
2012	46090376971.1726
2013	49777607129.37529
2014	53656538300.80009
2015	57949061364.28249
2016	62469088151.5761
2017	65779949822.9082