Year	Percent of Total
1960-01-01	4.27364779571414
1961-01-01	4.27704850299263
1962-01-01	4.27377943026854
1963-01-01	4.26396571735064
1964-01-01	4.24580322377056
1965-01-01	4.22083103501829
1966-01-01	4.22566125397235
1967-01-01	4.22053458938232
1968-01-01	4.20830849700098
1969-01-01	4.19282322890471
1970-01-01	4.17704854556895
1971-01-01	4.19829048805400
1972-01-01	4.21363138041883
1973-01-01	4.21966185574513
1974-01-01	4.21397778183129
1975-01-01	4.19420580809727
1976-01-01	4.18471115677155
1977-01-01	4.16295355381033
1978-01-01	4.13261892046661
1979-01-01	4.09888905686152
1980-01-01	4.06383241814859
1981-01-01	4.06805141066764
1982-01-01	4.07239720447876
1983-01-01	4.07922639688778
1984-01-01	4.08941265223143
1985-01-01	4.10055210189975
1986-01-01	4.13191622423678
1987-01-01	4.16254769053269
1988-01-01	4.19051747382056
1989-01-01	4.21047421926851
1990-01-01	4.21924039457884
1991-01-01	4.23917279538849
1992-01-01	4.23964427297119
1993-01-01	4.23292216598583
1994-01-01	4.23441787217486
1995-01-01	4.24972989606321
1996-01-01	4.31730351211035
1997-01-01	4.38183150846777
1998-01-01	4.43679838016532
1999-01-01	4.47375261209374
2000-01-01	4.48847032079538
2001-01-01	4.52762658706067
2002-01-01	4.55740173010526
2003-01-01	4.57343919520233
2004-01-01	4.56858461996723
2005-01-01	4.54096165101257
2006-01-01	4.52773671160149
2007-01-01	4.49026805906511
2008-01-01	4.44460556119464
2009-01-01	4.41147994090755
2010-01-01	4.40136022084231
2011-01-01	4.40037283823103
2012-01-01	4.40862077545255
2013-01-01	4.42116389222244
2014-01-01	4.43310956130274
2015-01-01	4.44008102471898
2016-01-01	4.47595335555837
2017-01-01	4.50580946287151