Year	2011 U.S. Dollars
1960-01-01	14926
1961-01-01	15697
1962-01-01	16438
1963-01-01	16383
1964-01-01	17711
1965-01-01	18416
1966-01-01	18693
1967-01-01	19580
1968-01-01	20541
1969-01-01	21764
1970-01-01	21828
1971-01-01	22367
1972-01-01	23168
1973-01-01	23894
1974-01-01	23589
1975-01-01	23234
1976-01-01	24588
1977-01-01	24993
1978-01-01	25483
1979-01-01	26423
1980-01-01	26292
1981-01-01	26073
1982-01-01	27059
1983-01-01	27799
1984-01-01	28973
1985-01-01	30129
1986-01-01	31580
1987-01-01	31623
1988-01-01	31563
1989-01-01	31731
1990-01-01	32188
1991-01-01	32568
1992-01-01	33053
1993-01-01	32907
1994-01-01	34617
1995-01-01	35509
1996-01-01	36293
1997-01-01	37295
1998-01-01	37969
1999-01-01	38814
2000-01-01	40049
2001-01-01	40190
2002-01-01	40239
2003-01-01	40289
2004-01-01	41111
2005-01-01	41996
2006-01-01	43276
2007-01-01	43774
2008-01-01	43177
2009-01-01	40441
2010-01-01	40782
2011-01-01	40930