Year	Percent of Total
1960-01-01	7.08213887607582
1961-01-01	6.90816517252346
1962-01-01	6.72748555156276
1963-01-01	6.55650326488478
1964-01-01	6.41538888643012
1965-01-01	6.31280993890540
1966-01-01	6.27760502063663
1967-01-01	6.27139012220421
1968-01-01	6.27525658113075
1969-01-01	6.26175944831092
1970-01-01	6.21880328526828
1971-01-01	6.22212162971702
1972-01-01	6.17185122692225
1973-01-01	6.09296551802501
1974-01-01	6.01429611776741
1975-01-01	5.94759709359580
1976-01-01	5.93560017872600
1977-01-01	5.93599896904801
1978-01-01	5.93000921135766
1979-01-01	5.88778277170897
1980-01-01	5.79728888077783
1981-01-01	5.70832808352197
1982-01-01	5.58154724389330
1983-01-01	5.44063275265977
1984-01-01	5.31533138532575
1985-01-01	5.22132395183098
1986-01-01	5.13591155448817
1987-01-01	5.06219991453869
1988-01-01	5.01036139263722
1989-01-01	4.99674387063797
1990-01-01	5.02957998028764
1991-01-01	5.12945537760958
1992-01-01	5.25965557366335
1993-01-01	5.38736886240365
1994-01-01	5.46793275472852
1995-01-01	5.47852022968463
1996-01-01	5.53205837994486
1997-01-01	5.52571192259158
1998-01-01	5.49238495328690
1999-01-01	5.47850098197353
2000-01-01	5.50673702496262
2001-01-01	5.59359124973048
2002-01-01	5.69504759565166
2003-01-01	5.77036068894148
2004-01-01	5.76173264847520
2005-01-01	5.64286812021957
2006-01-01	5.47577110555852
2007-01-01	5.24336573071380
2008-01-01	4.98402407771212
2009-01-01	4.73895110097193
2010-01-01	4.52328949676127
2011-01-01	4.45479888591892
2012-01-01	4.38711587262885
2013-01-01	4.32324596467720
2014-01-01	4.28047752852769
2015-01-01	4.27911066950069
2016-01-01	4.35623887836495
2017-01-01	4.48876341020364