Year	Percent of Total
1960-01-01	2.47612583197858
1961-01-01	2.48672768373230
1962-01-01	2.48774529108424
1963-01-01	2.48294223008998
1964-01-01	2.47805289049547
1965-01-01	2.47608806759726
1966-01-01	2.49196611539426
1967-01-01	2.51471750044599
1968-01-01	2.54024346293998
1969-01-01	2.56302386628386
1970-01-01	2.57876847833058
1971-01-01	2.63078282701960
1972-01-01	2.67245424683247
1973-01-01	2.70791024643740
1974-01-01	2.74308223895805
1975-01-01	2.77423165596479
1976-01-01	2.91831003308969
1977-01-01	3.07463786971984
1978-01-01	3.24859434796192
1979-01-01	3.43590303468026
1980-01-01	3.63290619038106
1981-01-01	3.73286547268137
1982-01-01	3.82256100767323
1983-01-01	3.90905149149185
1984-01-01	4.00069081817288
1985-01-01	4.10214203720950
1986-01-01	4.22758602492575
1987-01-01	4.36128513713164
1988-01-01	4.49424445172859
1989-01-01	4.61269787833113
1990-01-01	4.70949020142669
1991-01-01	4.83481041032759
1992-01-01	4.93325675281359
1993-01-01	5.01687614692261
1994-01-01	5.10287334501951
1995-01-01	5.20132934871305
1996-01-01	5.39253976538336
1997-01-01	5.59646143448802
1998-01-01	5.79644601354349
1999-01-01	5.97878142932729
2000-01-01	6.14118947470562
2001-01-01	6.25185837876502
2002-01-01	6.34716577967269
2003-01-01	6.43071843201869
2004-01-01	6.50896578614221
2005-01-01	6.58844536388208
2006-01-01	6.74050442228552
2007-01-01	6.90600861812562
2008-01-01	7.09783723461683
2009-01-01	7.33289711452512
2010-01-01	7.62735835827414
2011-01-01	8.01248258425305
2012-01-01	8.44307072686379
2013-01-01	8.91196456595687
2014-01-01	9.41522519147420
2015-01-01	9.95405953046395
2016-01-01	10.44074629278080
2017-01-01	10.94536722476130