Year	Percent of Total
1960-01-01	2.04471779195952
1961-01-01	2.14016072956877
1962-01-01	2.25391161335855
1963-01-01	2.37892449609856
1964-01-01	2.51077545676108
1965-01-01	2.64989817915357
1966-01-01	2.77063963969597
1967-01-01	2.90009935029198
1968-01-01	3.03700899309218
1969-01-01	3.18024622910080
1970-01-01	3.32931201714046
1971-01-01	3.47791897109156
1972-01-01	3.62269846790829
1973-01-01	3.77309460252508
1974-01-01	3.93639249659990
1975-01-01	4.11253821222543
1976-01-01	4.24830747507086
1977-01-01	4.38917242436874
1978-01-01	4.52381857404175
1979-01-01	4.63796275417630
1980-01-01	4.72575361777999
1981-01-01	4.85423634574561
1982-01-01	4.96556413919881
1983-01-01	5.06654171806651
1984-01-01	5.16900653605154
1985-01-01	5.27951033714219
1986-01-01	5.34370342333827
1987-01-01	5.40548113013153
1988-01-01	5.46920079029731
1989-01-01	5.53426495035820
1990-01-01	5.59882613502434
1991-01-01	5.72759537165315
1992-01-01	5.86358139518843
1993-01-01	6.00817377359937
1994-01-01	6.16789992172153
1995-01-01	6.35073397878968
1996-01-01	6.49187789687036
1997-01-01	6.66590849612305
1998-01-01	6.87144909203953
1999-01-01	7.10055514497722
2000-01-01	7.34506739976903
2001-01-01	7.53186477783426
2002-01-01	7.70464716373516
2003-01-01	7.85379692396033
2004-01-01	8.00999533185051
2005-01-01	8.22927062361029
2006-01-01	8.45874618730974
2007-01-01	8.65292291984326
2008-01-01	8.78951596428776
2009-01-01	8.89224447479598
2010-01-01	9.01955598578864
2011-01-01	9.41936628106129
2012-01-01	9.90467008084678
2013-01-01	10.45868397043220
2014-01-01	11.05650122551040
2015-01-01	11.68614963483210
2016-01-01	12.29092985181740
2017-01-01	12.92160023990850