Year	Percent of Total
1960-01-01	53.4702903158308
1961-01-01	53.1635881847229
1962-01-01	52.8763342361353
1963-01-01	52.6419654512321
1964-01-01	52.5275730159830
1965-01-01	52.5607432886689
1966-01-01	52.3810365799107
1967-01-01	52.3909421253440
1968-01-01	52.5340852549334
1969-01-01	52.7366868916417
1970-01-01	52.9564850775278
1971-01-01	52.7753256382994
1972-01-01	52.6825622514703
1973-01-01	52.6538854362921
1974-01-01	52.6801889409097
1975-01-01	52.7545733983306
1976-01-01	52.2240325833410
1977-01-01	51.8093225621775
1978-01-01	51.4764927054437
1979-01-01	51.1900457222780
1980-01-01	50.9342626012803
1981-01-01	50.5834787450755
1982-01-01	50.2968467037237
1983-01-01	50.0764774006044
1984-01-01	49.9393814314314
1985-01-01	49.8911135654208
1986-01-01	49.7406657544339
1987-01-01	49.7250901377102
1988-01-01	49.8022784545136
1989-01-01	49.9250334306689
1990-01-01	50.0726413210198
1991-01-01	50.1562136336497
1992-01-01	50.2651709740994
1993-01-01	50.4135311532524
1994-01-01	50.6292576525407
1995-01-01	50.9240612873154
1996-01-01	51.0165557973260
1997-01-01	51.2005182825519
1998-01-01	51.4525567153547
1999-01-01	51.7340373795985
2000-01-01	52.0203556193351
2001-01-01	52.2348469785920
2002-01-01	52.4663357526853
2003-01-01	52.7048849263283
2004-01-01	52.9428408907530
2005-01-01	53.1717586269847
2006-01-01	53.2794693462174
2007-01-01	53.3833711330143
2008-01-01	53.4812602174852
2009-01-01	53.5726911428065
2010-01-01	53.6563032445460
2011-01-01	53.6883942527241
2012-01-01	53.7361259116549
2013-01-01	53.7932001541041
2014-01-01	53.8605198324143
2015-01-01	53.9449304713616
2016-01-01	54.0058685612032
2017-01-01	54.1101211079705