Year	Percent of Total
1960-01-01	54.0739732467648
1961-01-01	53.8134080066212
1962-01-01	53.6171915254800
1963-01-01	53.4774184879878
1964-01-01	53.3951900388183
1965-01-01	53.3684135498102
1966-01-01	53.1268861552925
1967-01-01	52.9823856796168
1968-01-01	52.9084247069948
1969-01-01	52.8755686759612
1970-01-01	52.8666072397132
1971-01-01	52.6578074180549
1972-01-01	52.5040527498965
1973-01-01	52.3971782042779
1974-01-01	52.3344043801201
1975-01-01	52.3108888143540
1976-01-01	52.1235476993893
1977-01-01	52.0049081140988
1978-01-01	51.9334275267097
1979-01-01	51.8909010222955
1980-01-01	51.8700115946056
1981-01-01	51.6670764312088
1982-01-01	51.5310966005222
1983-01-01	51.4536912478977
1984-01-01	51.4306604226475
1985-01-01	51.4582103789788
1986-01-01	51.3463586289690
1987-01-01	51.3097069395822
1988-01-01	51.3364385224220
1989-01-01	51.4177379774580
1990-01-01	51.5484413507571
1991-01-01	51.5786470925551
1992-01-01	51.6746429639209
1993-01-01	51.8221202555407
1994-01-01	52.0055562484947
1995-01-01	52.2134699663198
1996-01-01	52.2458888987152
1997-01-01	52.3200010230517
1998-01-01	52.4256458579850
1999-01-01	52.5562454958619
2000-01-01	52.7062388555526
2001-01-01	52.7076855909870
2002-01-01	52.7544578720780
2003-01-01	52.8299001951357
2004-01-01	52.9174475507064
2005-01-01	53.0097030210924
2006-01-01	53.0051775927956
2007-01-01	53.0272930505318
2008-01-01	53.0755429717101
2009-01-01	53.1526626550263
2010-01-01	53.2585233949888
2011-01-01	53.3226833905332
2012-01-01	53.4253994422537
2013-01-01	53.5605528339318
2014-01-01	53.7228198737756
2015-01-01	53.9087117316244
2016-01-01	54.0515670795024
2017-01-01	54.2312153111811