Year	Percent of Total
1960-01-01	7.27336342100701
1961-01-01	7.36464332052896
1962-01-01	7.43797455496584
1963-01-01	7.50770994843234
1964-01-01	7.60103633428039
1965-01-01	7.73941729305742
1966-01-01	7.99176632276761
1967-01-01	8.30585864115356
1968-01-01	8.65944501042124
1969-01-01	9.02082930209042
1970-01-01	9.36623282492830
1971-01-01	9.56048213248021
1972-01-01	9.68478101380820
1973-01-01	9.75365742674238
1974-01-01	9.78882937550321
1975-01-01	9.79799951056468
1976-01-01	9.82579815529220
1977-01-01	9.84270682871329
1978-01-01	9.84884262997370
1979-01-01	9.84359262093518
1980-01-01	9.83215012272184
1981-01-01	9.85802797797693
1982-01-01	9.85407052472137
1983-01-01	9.82085527160652
1984-01-01	9.77892631262502
1985-01-01	9.74323875416672
1986-01-01	9.87750329231188
1987-01-01	10.04341745758850
1988-01-01	10.22635318016170
1989-01-01	10.40176434289570
1990-01-01	10.55535890195950
1991-01-01	10.74829672841250
1992-01-01	10.92293911645200
1993-01-01	11.08955974573550
1994-01-01	11.26003299682230
1995-01-01	11.44108018564050
1996-01-01	11.59703943082020
1997-01-01	11.75203520806640
1998-01-01	11.90716964708590
1999-01-01	12.06536229859960
2000-01-01	12.22836225760590
2001-01-01	12.44554120579720
2002-01-01	12.69041098621240
2003-01-01	12.96145194451540
2004-01-01	13.24791917176740
2005-01-01	13.54123902681260
2006-01-01	13.83654418045690
2007-01-01	14.13175929265650
2008-01-01	14.48457760695710
2009-01-01	14.95151493195180
2010-01-01	15.55357958232200
2011-01-01	16.00054497606170
2012-01-01	16.55461525847870
2013-01-01	17.18267863133970
2014-01-01	17.80529642596990
2015-01-01	18.36671219037640
2016-01-01	18.93856466105520
2017-01-01	19.42576624461800