Year	Percent of Total
1960-01-01	65.8082552950247
1961-01-01	65.8837151457581
1962-01-01	66.0434119842746
1963-01-01	66.2271044703521
1964-01-01	66.3541584002560
1965-01-01	66.3841347291578
1966-01-01	66.2772058087208
1967-01-01	66.1204100048414
1968-01-01	65.9120091076640
1969-01-01	65.6828625103631
1970-01-01	65.4610302577954
1971-01-01	65.1504676564729
1972-01-01	64.8520112011344
1973-01-01	64.5798529319036
1974-01-01	64.3502519217105
1975-01-01	64.1719631002252
1976-01-01	64.0451359310657
1977-01-01	63.9836401660709
1978-01-01	63.9771551839741
1979-01-01	64.0145069827083
1980-01-01	64.0893864583186
1981-01-01	64.1779531854750
1982-01-01	64.2886753887573
1983-01-01	64.4089494521595
1984-01-01	64.5128074777830
1985-01-01	64.5733753929931
1986-01-01	64.5635313296177
1987-01-01	64.5165523183791
1988-01-01	64.4377230047253
1989-01-01	64.3448373224702
1990-01-01	64.2513397321750
1991-01-01	64.0589361073337
1992-01-01	63.8997285287066
1993-01-01	63.7672440679857
1994-01-01	63.6761991099578
1995-01-01	63.6501886510600
1996-01-01	63.6274237681522
1997-01-01	63.7195926012079
1998-01-01	63.8947933726291
1999-01-01	64.0934960723986
2000-01-01	64.2740192126679
2001-01-01	64.6093025540154
2002-01-01	64.8270526934340
2003-01-01	64.9763356034382
2004-01-01	65.1254821820785
2005-01-01	65.2888166704154
2006-01-01	65.2599462812425
2007-01-01	65.3323392165852
2008-01-01	65.4291433588578
2009-01-01	65.4301003341609
2010-01-01	65.2735073536491
2011-01-01	64.9883708793635
2012-01-01	64.5697206774995
2013-01-01	64.0538511387175
2014-01-01	63.5409648670874
2015-01-01	63.1051772585116
2016-01-01	62.7665696267550
2017-01-01	62.4799497028515