Year	Percent of Total
1960-01-01	2.71884529769151
1961-01-01	2.70292914395397
1962-01-01	2.68097860739729
1963-01-01	2.65472281578196
1964-01-01	2.62546181741664
1965-01-01	2.59464115487993
1966-01-01	2.60074014146764
1967-01-01	2.60412646160669
1968-01-01	2.59849221511674
1969-01-01	2.57628657676021
1970-01-01	2.53557827002189
1971-01-01	2.51189385334626
1972-01-01	2.47495169365443
1973-01-01	2.43274884229148
1974-01-01	2.39383708323462
1975-01-01	2.36309346569912
1976-01-01	2.36194257984621
1977-01-01	2.36137220341489
1978-01-01	2.36374485628599
1979-01-01	2.37238763235985
1980-01-01	2.38878937154799
1981-01-01	2.42921096553826
1982-01-01	2.47340870130583
1983-01-01	2.51354153312283
1984-01-01	2.53890411848848
1985-01-01	2.54456147844193
1986-01-01	2.57293314824784
1987-01-01	2.59428063200754
1988-01-01	2.61458491930297
1989-01-01	2.64174481957621
1990-01-01	2.68010150512532
1991-01-01	2.74633127386320
1992-01-01	2.81673146300144
1993-01-01	2.88959750025036
1994-01-01	2.95944381204976
1995-01-01	3.02140822646847
1996-01-01	2.99835139981655
1997-01-01	2.96830183256144
1998-01-01	2.93284921152715
1999-01-01	2.89541554075222
2000-01-01	2.85853624576000
2001-01-01	2.85252144283838
2002-01-01	2.84552375198638
2003-01-01	2.83824174188743
2004-01-01	2.83026131666693
2005-01-01	2.82125884538392
2006-01-01	2.83907633941463
2007-01-01	2.85290719168578
2008-01-01	2.86528130643783
2009-01-01	2.88003032633842
2010-01-01	2.89855110685336
2011-01-01	2.92356775037629
2012-01-01	2.95518411311707
2013-01-01	2.98553786124959
2014-01-01	3.00359051975301
2015-01-01	3.00469903532041
2016-01-01	3.00036895626832
2017-01-01	2.97918538098595