Year	Percent of Total
1960-01-01	4.29615273081354
1961-01-01	4.29419569494915
1962-01-01	4.28686785369454
1963-01-01	4.26854454291089
1964-01-01	4.23497200151437
1965-01-01	4.18356498202062
1966-01-01	4.19279986451837
1967-01-01	4.18589982677791
1968-01-01	4.16636283258438
1969-01-01	4.13671312673667
1970-01-01	4.09934002621522
1971-01-01	4.12501783226197
1972-01-01	4.14067758168769
1973-01-01	4.14649421403202
1974-01-01	4.14250215512769
1975-01-01	4.12784553369433
1976-01-01	4.14637280262606
1977-01-01	4.15597190561097
1978-01-01	4.15692179762830
1979-01-01	4.14739190696731
1980-01-01	4.12760475493471
1981-01-01	4.11795310800210
1982-01-01	4.09828000482875
1983-01-01	4.07210199207022
1984-01-01	4.04454278056421
1985-01-01	4.01874246459689
1986-01-01	4.02590747732095
1987-01-01	4.02875389620665
1988-01-01	4.02706877497116
1989-01-01	4.02096587562503
1990-01-01	4.01006197742688
1991-01-01	4.00710005625909
1992-01-01	3.99869888529873
1993-01-01	3.98510383745617
1994-01-01	3.96600635927129
1995-01-01	3.94190828053366
1996-01-01	3.94275487576332
1997-01-01	3.93212538335415
1998-01-01	3.91281444716092
1999-01-01	3.88662284972588
2000-01-01	3.85482129627115
2001-01-01	3.85235333305673
2002-01-01	3.84076003451724
2003-01-01	3.82038669752478
2004-01-01	3.79140900352056
2005-01-01	3.75451499669324
2006-01-01	3.75759384524287
2007-01-01	3.75188268861967
2008-01-01	3.73637692946035
2009-01-01	3.70957011781855
2010-01-01	3.67146413698923
2011-01-01	3.69189793110289
2012-01-01	3.69854374294052
2013-01-01	3.69408485498771
2014-01-01	3.68096501920542
2015-01-01	3.65988429642991
2016-01-01	3.65851720958051
2017-01-01	3.65486319187479