Year	2010 U.S. Dollars
1981-01-01	227.783443542875
1982-01-01	223.577659886570
1983-01-01	234.726716121728
1984-01-01	220.927145248845
1985-01-01	190.140249700267
1986-01-01	201.974532556495
1987-01-01	222.709598908562
1988-01-01	216.663971471482
1989-01-01	208.786873814036
1990-01-01	207.219781415404
1991-01-01	185.729900467258
1992-01-01	163.623280621142
1993-01-01	178.608647306301
1994-01-01	177.994872815621
1995-01-01	182.708878237354
1996-01-01	199.005021700008
1997-01-01	199.111302852145
1998-01-01	186.661401899107
1999-01-01	190.691548272396
2000-01-01	196.504962197176
2001-01-01	206.743143498219
2002-01-01	203.905912851548
2003-01-01	193.866915123197
2004-01-01	214.044831566806
2005-01-01	232.783200207957
2006-01-01	251.056046543600
2007-01-01	272.391198046680
2008-01-01	293.853313282981
2009-01-01	311.367743764672
2010-01-01	341.309909200504
2011-01-01	369.584420036853
2012-01-01	391.131795305971
2013-01-01	421.384135742307
2014-01-01	452.778236052888
2015-01-01	487.290010568135
2016-01-01	511.187426515801
2017-01-01	549.847872764768