Year	Percent of Total
1960-01-01	64.5599466040436
1961-01-01	64.6233334460759
1962-01-01	64.6878357295666
1963-01-01	64.7753034192244
1964-01-01	64.9026222054790
1965-01-01	65.0690976130362
1966-01-01	65.1511485530358
1967-01-01	65.3757985033765
1968-01-01	65.6615553081775
1969-01-01	65.8958973314517
1970-01-01	66.0182405046535
1971-01-01	65.9935875895891
1972-01-01	65.8367822534256
1973-01-01	65.6095959185416
1974-01-01	65.4108081049199
1975-01-01	65.2886482044596
1976-01-01	65.1375693216747
1977-01-01	65.0593956402874
1978-01-01	65.0457662080764
1979-01-01	65.1013910520682
1980-01-01	65.2358569960187
1981-01-01	65.5233403701260
1982-01-01	65.9906077724086
1983-01-01	66.5752058787065
1984-01-01	67.1630186037187
1985-01-01	67.6730406886926
1986-01-01	67.9589704296296
1987-01-01	68.1144631048195
1988-01-01	68.2162247392324
1989-01-01	68.3707561649340
1990-01-01	68.6295246548805
1991-01-01	68.6881811897500
1992-01-01	68.8478553107635
1993-01-01	69.0761747488964
1994-01-01	69.3032746427528
1995-01-01	69.4842307599605
1996-01-01	69.6659458649595
1997-01-01	69.7837224685669
1998-01-01	69.8646764347256
1999-01-01	69.9591815796065
2000-01-01	70.0899522705317
2001-01-01	70.1691705027638
2002-01-01	70.2976566492176
2003-01-01	70.4338185940929
2004-01-01	70.5105878690187
2005-01-01	70.4872710805743
2006-01-01	70.3908740981470
2007-01-01	70.1753479818370
2008-01-01	69.8765347946050
2009-01-01	69.5640809973745
2010-01-01	69.2759714605353
2011-01-01	68.8621900073828
2012-01-01	68.5227554006766
2013-01-01	68.1921999652489
2014-01-01	67.7821372434924
2015-01-01	67.2556907018934
2016-01-01	66.6676612787567
2017-01-01	65.9758574137394