Year	Percent of Total
1960-01-01	8.63565363479803
1961-01-01	8.50038736569054
1962-01-01	8.38846616682794
1963-01-01	8.29587542037639
1964-01-01	8.21300275524795
1965-01-01	8.13589198388058
1966-01-01	8.20589693155291
1967-01-01	8.26810168884469
1968-01-01	8.32942674125913
1969-01-01	8.39867256206551
1970-01-01	8.47992131669639
1971-01-01	8.52867227574541
1972-01-01	8.57006518787338
1973-01-01	8.60765455646919
1974-01-01	8.65123889898583
1975-01-01	8.71170846480914
1976-01-01	8.91638277407296
1977-01-01	9.14029117289680
1978-01-01	9.36865203601457
1979-01-01	9.57947524588580
1980-01-01	9.76279619489999
1981-01-01	9.90524603548755
1982-01-01	10.01483751649270
1983-01-01	10.10962055571230
1984-01-01	10.21274509441150
1985-01-01	10.33450460737840
1986-01-01	10.48997296298460
1987-01-01	10.65141570940420
1988-01-01	10.81753676797110
1989-01-01	10.97791492125610
1990-01-01	11.12292138243740
1991-01-01	11.21848312764610
1992-01-01	11.31277544608740
1993-01-01	11.40390252223050
1994-01-01	11.48705357771230
1995-01-01	11.55756181876360
1996-01-01	11.62390187200610
1997-01-01	11.67227468991530
1998-01-01	11.71369042176290
1999-01-01	11.75970651609390
2000-01-01	11.81643218876190
2001-01-01	11.84449682223310
2002-01-01	11.87884253304020
2003-01-01	11.92515593342630
2004-01-01	11.98631127344660
2005-01-01	12.06312396396440
2006-01-01	12.22040475241150
2007-01-01	12.38021039173890
2008-01-01	12.55718067234260
2009-01-01	12.77632241790300
2010-01-01	13.05274387411440
2011-01-01	13.28930498046220
2012-01-01	13.59442564176140
2013-01-01	13.94428854548070
2014-01-01	14.30203429172050
2015-01-01	14.64716248581650
2016-01-01	14.99839191835450
2017-01-01	15.32171452444610