Year	Percent of Total
1960-01-01	64.1895911048458
1961-01-01	64.2710803382815
1962-01-01	64.4232973841912
1963-01-01	64.6001870567245
1964-01-01	64.7384669710513
1965-01-01	64.8097872894636
1966-01-01	64.7550592756740
1967-01-01	64.6901579385697
1968-01-01	64.6064337777441
1969-01-01	64.5107832949706
1970-01-01	64.4130148982782
1971-01-01	64.2872632746190
1972-01-01	64.1552848125235
1973-01-01	64.0423794079942
1974-01-01	63.9840687711138
1975-01-01	63.9974211536900
1976-01-01	64.0049223943556
1977-01-01	64.0926850753721
1978-01-01	64.2526258931559
1979-01-01	64.4709689380541
1980-01-01	64.7395317475109
1981-01-01	65.0313211056216
1982-01-01	65.3828774889238
1983-01-01	65.7691303258238
1984-01-01	66.1476668169125
1985-01-01	66.4844826497294
1986-01-01	66.7594131923216
1987-01-01	66.9587165205245
1988-01-01	67.1060730616517
1989-01-01	67.2389720723356
1990-01-01	67.3697242718749
1991-01-01	67.3761781975546
1992-01-01	67.4103622634942
1993-01-01	67.4411481056080
1994-01-01	67.4376081057173
1995-01-01	67.3940662418512
1996-01-01	67.2359872575102
1997-01-01	67.0847456406764
1998-01-01	66.9359115640599
1999-01-01	66.7969177195424
2000-01-01	66.6767767656445
2001-01-01	66.5599054284926
2002-01-01	66.4428665792759
2003-01-01	66.3312646371762
2004-01-01	66.2257316212951
2005-01-01	66.1193477620127
2006-01-01	65.9768018054836
2007-01-01	65.8364956068210
2008-01-01	65.6919001163194
2009-01-01	65.5403372184697
2010-01-01	65.3825742001035
2011-01-01	65.1571332537924
2012-01-01	64.9418606723630
2013-01-01	64.6884778274995
2014-01-01	64.3967581428673
2015-01-01	64.1093959159350
2016-01-01	63.9748103510759
2017-01-01	63.8375415165924