Year	US Dollars adjusted for inflation)
1980	873.14531
1981	878.97446
1982	908.37193
1983	926.24271
1984	938.15886
1985	932.89671
1986	923.23488
1987	911.21719
1988	908.43077
1989	853.85463
1990	871.24903
1991	800.36475
1992	843.6138
1993	844.16464
1994	777.12889
1995	782.96773
1996	751.92393
1997	761.46218
1998	751.12934
1999	746.09241
2000	806.42947
2001	805.15553
2002	804.21132
2003	801.79876
2004	798.01057
2005	801.33346
2006	803.11305
2007	790.36748
2008	774.68492
2009	770.99471
2010	769.17429
2011	770.32276
2012	774.47099
2013	782.5169
2014	779.83982
2015	769.47738
2016	768.43896
2017	769.92977