Year	Percent of Total
1960-01-01	3.21110930438408
1961-01-01	3.18961944907313
1962-01-01	3.15466391361366
1963-01-01	3.10651540296268
1964-01-01	3.04288680461087
1965-01-01	2.96219778418967
1966-01-01	2.93935442994449
1967-01-01	2.91499276183249
1968-01-01	2.89056316747011
1969-01-01	2.86971345619235
1970-01-01	2.85674174033643
1971-01-01	2.86782677284960
1972-01-01	2.87148589016997
1973-01-01	2.87008676511769
1974-01-01	2.86575445701517
1975-01-01	2.85922190333241
1976-01-01	2.88550612610090
1977-01-01	2.90593933214377
1978-01-01	2.91953832939577
1979-01-01	2.92404476083737
1980-01-01	2.91821750570320
1981-01-01	2.93217839439638
1982-01-01	2.94192309882521
1983-01-01	2.94758707015113
1984-01-01	2.95105114677650
1985-01-01	2.95367898004115
1986-01-01	2.96312150343934
1987-01-01	2.96746188919081
1988-01-01	2.96870847208542
1989-01-01	2.96874461699888
1990-01-01	2.96912546805600
1991-01-01	2.97771587815482
1992-01-01	2.98334368150419
1993-01-01	2.98605681874652
1994-01-01	2.98479071927894
1995-01-01	2.97915968651557
1996-01-01	2.96134497496498
1997-01-01	2.93636569530258
1998-01-01	2.90684615142948
1999-01-01	2.87512454141406
2000-01-01	2.84284842547844
2001-01-01	2.83471282941134
2002-01-01	2.81960943522121
2003-01-01	2.79956916578826
2004-01-01	2.77640760900792
2005-01-01	2.75128675966011
2006-01-01	2.75150262290948
2007-01-01	2.74738073343632
2008-01-01	2.73929873692670
2009-01-01	2.72786926472465
2010-01-01	2.71399819651137
2011-01-01	2.73472507973162
2012-01-01	2.75166550477135
2013-01-01	2.76584464346464
2014-01-01	2.77806558798934
2015-01-01	2.78926146336386
2016-01-01	2.81592779950079
2017-01-01	2.83850584544610