Year	Percent of Total
1960-01-01	3.22252654378674
1961-01-01	3.25559598353081
1962-01-01	3.28516954113926
1963-01-01	3.31262046967027
1964-01-01	3.34148625150479
1965-01-01	3.37271164349132
1966-01-01	3.43868158781535
1967-01-01	3.50297939728221
1968-01-01	3.56307151329199
1969-01-01	3.61554477859932
1970-01-01	3.65920789900782
1971-01-01	3.73271884593759
1972-01-01	3.79458060600095
1973-01-01	3.84527694617870
1974-01-01	3.88457161965347
1975-01-01	3.91188783191518
1976-01-01	3.97365911674616
1977-01-01	4.01917542885140
1978-01-01	4.05016081866249
1979-01-01	4.06811316598955
1980-01-01	4.07380349864190
1981-01-01	4.09846165902832
1982-01-01	4.10985771082976
1983-01-01	4.10896597695931
1984-01-01	4.09813328752378
1985-01-01	4.08001322014757
1986-01-01	4.07773644692957
1987-01-01	4.07304145613987
1988-01-01	4.06359692767785
1989-01-01	4.04617397179535
1990-01-01	4.02057429773406
1991-01-01	4.02836185427516
1992-01-01	4.02347374940351
1993-01-01	4.01148365259295
1994-01-01	3.99903008647266
1995-01-01	3.98940843289463
1996-01-01	4.00950191405418
1997-01-01	4.02755144847399
1998-01-01	4.04460480211681
1999-01-01	4.06088574101322
2000-01-01	4.07694287184766
2001-01-01	4.11662055639030
2002-01-01	4.15257597484836
2003-01-01	4.18489192732354
2004-01-01	4.21353766753977
2005-01-01	4.23864704594553
2006-01-01	4.29896220366382
2007-01-01	4.35481671912272
2008-01-01	4.40270709134408
2009-01-01	4.43733653240122
2010-01-01	4.45726071308531
2011-01-01	4.49621066580819
2012-01-01	4.52226167023513
2013-01-01	4.54561140883393
2014-01-01	4.57937627796580
2015-01-01	4.63087643698416
2016-01-01	4.70984852130487
2017-01-01	4.79984526322145