Year	Percent of Total
1960-01-01	38.9962166510839
1961-01-01	39.8296424295994
1962-01-01	40.2085402961491
1963-01-01	40.1838220175186
1964-01-01	39.9685213393384
1965-01-01	39.7738867088592
1966-01-01	39.8147875937087
1967-01-01	39.9359656433819
1968-01-01	40.1809593194049
1969-01-01	40.4710439240198
1970-01-01	40.7480689046134
1971-01-01	41.7389188038088
1972-01-01	42.3459399543557
1973-01-01	42.6572027575169
1974-01-01	42.8157986358385
1975-01-01	42.9259024699177
1976-01-01	43.3868559252362
1977-01-01	43.9004235099680
1978-01-01	44.4119817340018
1979-01-01	44.8040440428808
1980-01-01	45.0297748560896
1981-01-01	45.7366435831797
1982-01-01	46.0852192962157
1983-01-01	46.2108496549511
1984-01-01	46.2751603185833
1985-01-01	46.3623623131393
1986-01-01	46.3764807478323
1987-01-01	46.3755013213120
1988-01-01	46.3678310894965
1989-01-01	46.2970613002731
1990-01-01	46.1159806633450
1991-01-01	46.4721698843488
1992-01-01	46.6886389757052
1993-01-01	46.7595834019267
1994-01-01	46.7131031250090
1995-01-01	46.5858455501335
1996-01-01	46.6124984954974
1997-01-01	46.5309718668036
1998-01-01	46.3788089692526
1999-01-01	46.1955630657008
2000-01-01	46.0161351599715
2001-01-01	46.1460296970866
2002-01-01	46.2249942616344
2003-01-01	46.2679645604692
2004-01-01	46.2818887537512
2005-01-01	46.2674248236399
2006-01-01	46.3767445260664
2007-01-01	46.4269749648500
2008-01-01	46.4218807834961
2009-01-01	46.3665861572617
2010-01-01	46.2703343499893
2011-01-01	46.2462844208220
2012-01-01	46.1728237497399
2013-01-01	46.0517370829398
2014-01-01	45.8825289959809
2015-01-01	45.6694259174045
2016-01-01	45.5320846053056
2017-01-01	45.3287396551790