Year	US Dollars
1982	8310
1983	8730
1984	9210
1985	8090
1986	7450
1987	7830
1988	7570
1989	7310
1990	7220
1991	9800
1992	9880
1993	10030
1994	9680
1995	10380
1996	10790
1997	10310
1998	10070
1999	9870
2000	10940
2001	11500
2002	12100
2003	12950
2004	14580
2005	16550
2006	17890
2007	19660
2008	20860
2009	18830
2010	18970
2011	18440
2012	19910
2013	21710
2014	21010
2015	22660
2016	21350
2017	20240