Year	Percent of Total
1960-01-01	8.40729273796043
1961-01-01	8.49581463440543
1962-01-01	8.58829238586553
1963-01-01	8.68105124339777
1964-01-01	8.77538384005010
1965-01-01	8.87343947068338
1966-01-01	9.00742858920020
1967-01-01	9.13905539790997
1968-01-01	9.27093045467629
1969-01-01	9.39516204594943
1970-01-01	9.51608968112313
1971-01-01	9.66591213224813
1972-01-01	9.80001651211753
1973-01-01	9.92576716575775
1974-01-01	10.04510284593320
1975-01-01	10.16458775319310
1976-01-01	10.32416734871810
1977-01-01	10.48620055636350
1978-01-01	10.63762025297230
1979-01-01	10.75293135038250
1980-01-01	10.81871587646900
1981-01-01	10.85942490230410
1982-01-01	10.84469908311710
1983-01-01	10.80925323090790
1984-01-01	10.80018142725440
1985-01-01	10.84260303008400
1986-01-01	10.95283052797470
1987-01-01	11.10081026593270
1988-01-01	11.27225341171420
1989-01-01	11.44335848574790
1990-01-01	11.60083926793620
1991-01-01	11.76377312940740
1992-01-01	11.91180959689390
1993-01-01	12.04737418457090
1994-01-01	12.17515723458600
1995-01-01	12.29924169232030
1996-01-01	12.44061655710300
1997-01-01	12.57337376039150
1998-01-01	12.70189497874690
1999-01-01	12.82935290083430
2000-01-01	12.95982908275380
2001-01-01	13.10907542245350
2002-01-01	13.25812952067820
2003-01-01	13.40811609589550
2004-01-01	13.55679431234920
2005-01-01	13.70526600408180
2006-01-01	13.86806191366090
2007-01-01	14.02564562446050
2008-01-01	14.19081196357820
2009-01-01	14.38465821501380
2010-01-01	14.62253599276710
2011-01-01	14.87920685927100
2012-01-01	15.18098949269020
2013-01-01	15.51215333718290
2014-01-01	15.84997978918220
2015-01-01	16.18249559762630
2016-01-01	16.50400334508420
2017-01-01	16.81091855246670