Year	Percent of Total
1960-01-01	6.17946908983643
1961-01-01	6.08854840922494
1962-01-01	5.99481807633005
1963-01-01	5.91196895234075
1964-01-01	5.85884656705919
1965-01-01	5.84327223245017
1966-01-01	5.92959787269482
1967-01-01	6.04194667402064
1968-01-01	6.16299160805428
1969-01-01	6.26504032287641
1970-01-01	6.33481317940263
1971-01-01	6.44607981636629
1972-01-01	6.50984866188894
1973-01-01	6.56400191359117
1974-01-01	6.65498136947714
1975-01-01	6.80018546931290
1976-01-01	7.01054205796468
1977-01-01	7.26269126005845
1978-01-01	7.50597391264643
1979-01-01	7.67471479474430
1980-01-01	7.74490141496988
1981-01-01	7.77270361706232
1982-01-01	7.71122504068603
1983-01-01	7.61009339262993
1984-01-01	7.53988862230467
1985-01-01	7.53844204724365
1986-01-01	7.64031021603912
1987-01-01	7.78184234454781
1988-01-01	7.94875361293833
1989-01-01	8.12179494406129
1990-01-01	8.29263016840065
1991-01-01	8.47704099481020
1992-01-01	8.65880909548643
1993-01-01	8.82203582026840
1994-01-01	8.94330251213887
1995-01-01	9.01075388757345
1996-01-01	9.17899274572972
1997-01-01	9.27772232505028
1998-01-01	9.33325872431750
1999-01-01	9.37801605151940
2000-01-01	9.42250925890882
2001-01-01	9.57208269969813
2002-01-01	9.72033339909630
2003-01-01	9.84783943795806
2004-01-01	9.92248106670200
2005-01-01	9.92662046963958
2006-01-01	10.04716833183340
2007-01-01	10.12025967816590
2008-01-01	10.15537135407550
2009-01-01	10.16191248132340
2010-01-01	10.14706642043380
2011-01-01	10.14416653095820
2012-01-01	10.06798973808350
2013-01-01	9.95001429285720
2014-01-01	9.87857557570273
2015-01-01	9.93829285928608
2016-01-01	10.32575066361090
2017-01-01	10.86351442481900