Year	Percent of Total
1960-01-01	2.81648650033301
1961-01-01	2.81154356095808
1962-01-01	2.80331376791670
1963-01-01	2.78452733281896
1964-01-01	2.76150534771224
1965-01-01	2.73336329972816
1966-01-01	2.71885208617624
1967-01-01	2.70421577742455
1968-01-01	2.70346081674501
1969-01-01	2.71577903179015
1970-01-01	2.73949047468211
1971-01-01	2.78096104555038
1972-01-01	2.82044995307705
1973-01-01	2.86540913400242
1974-01-01	2.91020350078270
1975-01-01	2.95975317526547
1976-01-01	3.04939590940125
1977-01-01	3.13400161308906
1978-01-01	3.21536439398177
1979-01-01	3.27571692374538
1980-01-01	3.31162496374614
1981-01-01	3.30190792547506
1982-01-01	3.24573616428820
1983-01-01	3.14649212320289
1984-01-01	3.03762999131435
1985-01-01	2.95826579301842
1986-01-01	3.02707205331112
1987-01-01	3.12408759124088
1988-01-01	3.23024380988521
1989-01-01	3.31270720507382
1990-01-01	3.37441713925646
1991-01-01	3.40715586884207
1992-01-01	3.43310631083570
1993-01-01	3.47068564160407
1994-01-01	3.52208867609734
1995-01-01	3.58556850499080
1996-01-01	3.72076266742064
1997-01-01	3.85954561504664
1998-01-01	4.00173398255509
1999-01-01	4.14634774545829
2000-01-01	4.29448111338711
2001-01-01	4.42942227269525
2002-01-01	4.56478616850200
2003-01-01	4.71108535648031
2004-01-01	4.86704398768742
2005-01-01	5.04225418422353
2006-01-01	5.27669179931118
2007-01-01	5.53082572891164
2008-01-01	5.79149552205913
2009-01-01	6.04410707091245
2010-01-01	6.27809722948249
2011-01-01	6.47561730339494
2012-01-01	6.64659573136844
2013-01-01	6.81392764177708
2014-01-01	7.00512552453137
2015-01-01	7.23360581943894
2016-01-01	7.48551076343288
2017-01-01	7.77542604953234