Year	Percent of Total
1960-01-01	41.3201490571695
1961-01-01	41.6241025787708
1962-01-01	41.8378550119488
1963-01-01	41.9889650009418
1964-01-01	42.1088119178880
1965-01-01	42.2146450055750
1966-01-01	42.5254115821149
1967-01-01	42.7958800071645
1968-01-01	43.0233227905347
1969-01-01	43.1928155662250
1970-01-01	43.2977100593820
1971-01-01	43.6314129707598
1972-01-01	43.8533756851513
1973-01-01	43.9983387525097
1974-01-01	44.1146012088329
1975-01-01	44.2287122768621
1976-01-01	44.5626476222566
1977-01-01	44.8780617399614
1978-01-01	45.1637229572585
1979-01-01	45.3995829521186
1980-01-01	45.5811309156608
1981-01-01	45.9453040445745
1982-01-01	46.2016511007222
1983-01-01	46.3853434964762
1984-01-01	46.5327232878720
1985-01-01	46.6552327816574
1986-01-01	46.8982916249196
1987-01-01	47.0754254906559
1988-01-01	47.1934904242964
1989-01-01	47.2527113904331
1990-01-01	47.2532281682263
1991-01-01	47.3391738684414
1992-01-01	47.3612615012854
1993-01-01	47.3257090622368
1994-01-01	47.2403446085341
1995-01-01	47.1139492469582
1996-01-01	47.1349098044925
1997-01-01	47.0909599939844
1998-01-01	47.0028327816435
1999-01-01	46.8923088540590
2000-01-01	46.7698494703023
2001-01-01	46.7832835074164
2002-01-01	46.7524953022427
2003-01-01	46.6882255896877
2004-01-01	46.6001906747127
2005-01-01	46.4959361284107
2006-01-01	46.5122327959213
2007-01-01	46.4888313032938
2008-01-01	46.4323024132649
2009-01-01	46.3436042522409
2010-01-01	46.2233559456431
2011-01-01	46.1820814251845
2012-01-01	46.0817600832673
2013-01-01	45.9383368429278
2014-01-01	45.7671928036753
2015-01-01	45.5739404672087
2016-01-01	45.3875923614989
2017-01-01	45.1814120096187