Year	Percent of Total
1960-01-01	1.63315453537503
1961-01-01	1.64090962510283
1962-01-01	1.65076719728751
1963-01-01	1.66372078669023
1964-01-01	1.69059971800523
1965-01-01	1.70920753708406
1966-01-01	1.72177477254037
1967-01-01	1.73205448701597
1968-01-01	1.74651258461423
1969-01-01	1.76377376889322
1970-01-01	1.76925736495106
1971-01-01	1.86524508317197
1972-01-01	1.97061207713474
1973-01-01	2.08128409192524
1974-01-01	2.20843319434869
1975-01-01	2.33524723626703
1976-01-01	2.42281281123866
1977-01-01	2.51751695271705
1978-01-01	2.62872628726287
1979-01-01	2.75323043085503
1980-01-01	2.88477235842624
1981-01-01	2.96661501619946
1982-01-01	3.04941876480635
1983-01-01	3.15344428286745
1984-01-01	3.27743701792719
1985-01-01	3.41763030573380
1986-01-01	3.51583467525497
1987-01-01	3.60813326880962
1988-01-01	3.70970458720012
1989-01-01	3.83071156349493
1990-01-01	3.97066262013151
1991-01-01	4.11431737522275
1992-01-01	4.25408948585140
1993-01-01	4.39428399776853
1994-01-01	4.52584697693310
1995-01-01	4.65097107054774
1996-01-01	4.79467783331082
1997-01-01	4.92604938025189
1998-01-01	5.05723122992967
1999-01-01	5.19769020415322
2000-01-01	5.35315362874930
2001-01-01	5.57988759662662
2002-01-01	5.81008430093845
2003-01-01	6.03687687840014
2004-01-01	6.23723110203101
2005-01-01	6.41090390272850
2006-01-01	6.58312742675609
2007-01-01	6.72814831135312
2008-01-01	6.86955701575125
2009-01-01	7.04636659946870
2010-01-01	7.26587391184366
2011-01-01	7.54831598592167
2012-01-01	7.86632744275596
2013-01-01	8.21200311769291
2014-01-01	8.56013965595433
2015-01-01	8.90313170207111
2016-01-01	9.22490423337590
2017-01-01	9.55068836807141