Year	Percent of Total
1960-01-01	3.13864735397600
1961-01-01	3.17281167772867
1962-01-01	3.20435652997037
1963-01-01	3.22768649637486
1964-01-01	3.23707673973913
1965-01-01	3.23099217778269
1966-01-01	3.26163845302451
1967-01-01	3.27859554760119
1968-01-01	3.28653704592342
1969-01-01	3.29083324374156
1970-01-01	3.29450974036191
1971-01-01	3.33992279330610
1972-01-01	3.38141951516745
1973-01-01	3.41694433859667
1974-01-01	3.44419145441474
1975-01-01	3.46275286365960
1976-01-01	3.50313046402844
1977-01-01	3.53369785290406
1978-01-01	3.55595764083187
1979-01-01	3.57164742850585
1980-01-01	3.58230130240701
1981-01-01	3.61502913351945
1982-01-01	3.63873978121250
1983-01-01	3.65450018799306
1984-01-01	3.66396040416807
1985-01-01	3.66888892775908
1986-01-01	3.69976926367534
1987-01-01	3.72468229694794
1988-01-01	3.74429678611468
1989-01-01	3.75933567444461
1990-01-01	3.77107274911525
1991-01-01	3.82270333897381
1992-01-01	3.86874500558221
1993-01-01	3.91028271812102
1994-01-01	3.94873591174258
1995-01-01	3.98563093834070
1996-01-01	4.05551683942079
1997-01-01	4.11968605140197
1998-01-01	4.17999421860362
1999-01-01	4.23842532432776
2000-01-01	4.29641523088732
2001-01-01	4.37416243310507
2002-01-01	4.44859087721059
2003-01-01	4.51892380935300
2004-01-01	4.58369072979404
2005-01-01	4.64317365970288
2006-01-01	4.71975992580609
2007-01-01	4.78926984518882
2008-01-01	4.85351960141454
2009-01-01	4.91440779687496
2010-01-01	4.97430877746459
2011-01-01	5.06095840759968
2012-01-01	5.14492179903167
2013-01-01	5.23165299128102
2014-01-01	5.32731811453062
2015-01-01	5.43576394475378
2016-01-01	5.57567083871895
2017-01-01	5.71967061888090