Year	US Dollars
1990	19900
1991	20050
1992	19900
1993	19720
1994	21130
1995	22420
1996	23260
1997	24150
1998	25310
1999	27090
2000	29280
2001	29670
2002	30650
2003	32060
2004	33770
2005	34480
2006	38460
2007	41870
2008	43380
2009	40670
2010	42850
2011	44720
2012	45830
2013	46720
2014	47520
2015	48510
2016	49460
2017	50980