Year	Percent of Total
1960-01-01	2.79850130347293
1961-01-01	2.80754473443409
1962-01-01	2.80271452582040
1963-01-01	2.78386071508212
1964-01-01	2.75083824348927
1965-01-01	2.70416386357018
1966-01-01	2.71312076014858
1967-01-01	2.70996844580400
1968-01-01	2.69382949217236
1969-01-01	2.66420303308475
1970-01-01	2.62129045310752
1971-01-01	2.62425637106892
1972-01-01	2.61558240359531
1973-01-01	2.59654657343615
1974-01-01	2.56898061695368
1975-01-01	2.53484313223703
1976-01-01	2.54122587020754
1977-01-01	2.53150976105828
1978-01-01	2.50609356556039
1979-01-01	2.46645767412569
1980-01-01	2.41456118752722
1981-01-01	2.43231284559452
1982-01-01	2.42585577872953
1983-01-01	2.39125488356093
1984-01-01	2.32254776351019
1985-01-01	2.21148174708586
1986-01-01	2.24485888809461
1987-01-01	2.26890743883143
1988-01-01	2.27732042802945
1989-01-01	2.26110410016159
1990-01-01	2.21183344362703
1991-01-01	2.22553973835080
1992-01-01	2.24293554694862
1993-01-01	2.26390698066969
1994-01-01	2.29119172849043
1995-01-01	2.32948358087507
1996-01-01	2.32556077905237
1997-01-01	2.31213215603316
1998-01-01	2.29355928188927
1999-01-01	2.27224985616128
2000-01-01	2.24839995071106
2001-01-01	2.22779588526687
2002-01-01	2.21176843977115
2003-01-01	2.20008358172355
2004-01-01	2.19247257522800
2005-01-01	2.18961119626108
2006-01-01	2.21422019854442
2007-01-01	2.23410093898619
2008-01-01	2.25280758272752
2009-01-01	2.27504809881015
2010-01-01	2.30328491307918
2011-01-01	2.33738723256523
2012-01-01	2.37771768785689
2013-01-01	2.42028410212529
2014-01-01	2.45951067860634
2015-01-01	2.49313992141566
2016-01-01	2.54155755627188
2017-01-01	2.58052606184602