Year	Percent of Total
1960-01-01	4.59565029867747
1961-01-01	4.52885707736347
1962-01-01	4.44233170761448
1963-01-01	4.34344092533465
1964-01-01	4.24184579903514
1965-01-01	4.14116872492685
1966-01-01	4.08628862215809
1967-01-01	4.02794347582382
1968-01-01	3.96758697373582
1969-01-01	3.90527892260042
1970-01-01	3.84126781212922
1971-01-01	3.82216110930096
1972-01-01	3.79742120349938
1973-01-01	3.76864980351188
1974-01-01	3.73761160368229
1975-01-01	3.70504048804044
1976-01-01	3.73537574370102
1977-01-01	3.76205868264320
1978-01-01	3.78334238574800
1979-01-01	3.79634906730019
1980-01-01	3.80019947849345
1981-01-01	3.84690872030757
1982-01-01	3.88901323043566
1983-01-01	3.93004315465204
1984-01-01	3.97316833336182
1985-01-01	4.02002720737980
1986-01-01	4.08722583356961
1987-01-01	4.15669203301854
1988-01-01	4.23139713144077
1989-01-01	4.31430931753256
1990-01-01	4.40611506825020
1991-01-01	4.48310416228997
1992-01-01	4.56349370494329
1993-01-01	4.64440648489619
1994-01-01	4.72162775390993
1995-01-01	4.79297882806196
1996-01-01	4.85488522558573
1997-01-01	4.91198224335222
1998-01-01	4.96541724196618
1999-01-01	5.01574539101462
2000-01-01	5.06408528460658
2001-01-01	5.12078386370658
2002-01-01	5.17574417754059
2003-01-01	5.23472206773343
2004-01-01	5.30512645269305
2005-01-01	5.39073919864852
2006-01-01	5.49135687674277
2007-01-01	5.60368731732137
2008-01-01	5.72226351335515
2009-01-01	5.83914043071919
2010-01-01	5.95125628110304
2011-01-01	6.04917891760580
2012-01-01	6.14009917370869
2013-01-01	6.23286101198969
2014-01-01	6.33912062865177
2015-01-01	6.46546455123941
2016-01-01	6.57886446601828
2017-01-01	6.70380759347063