Year	Percent of Total
1960-01-01	5.03880183876230
1961-01-01	4.93017926158985
1962-01-01	4.81203791963655
1963-01-01	4.68170837405720
1964-01-01	4.54151514880766
1965-01-01	4.39143059612493
1966-01-01	4.29328106101681
1967-01-01	4.18577912497437
1968-01-01	4.08917746564198
1969-01-01	4.02364585574669
1970-01-01	4.00743158720642
1971-01-01	4.18950005860978
1972-01-01	4.39793751895663
1973-01-01	4.60687533195363
1974-01-01	4.78640577027603
1975-01-01	4.91331495505152
1976-01-01	5.01147442737491
1977-01-01	5.06296982597628
1978-01-01	5.07643350948378
1979-01-01	5.05674273675265
1980-01-01	5.00912240063909
1981-01-01	4.96395772319806
1982-01-01	4.91144860991977
1983-01-01	4.84823712454840
1984-01-01	4.76604491963400
1985-01-01	4.66596205910452
1986-01-01	4.57582070253574
1987-01-01	4.46854810660741
1988-01-01	4.37102444558363
1989-01-01	4.31673349563225
1990-01-01	4.32106890368927
1991-01-01	4.31910017317551
1992-01-01	4.36492244284163
1993-01-01	4.43777200865008
1994-01-01	4.51212693455992
1995-01-01	4.57819683548045
1996-01-01	4.67383699498211
1997-01-01	4.76143810865438
1998-01-01	4.84972071992198
1999-01-01	4.95255521540753
2000-01-01	5.07333150990969
2001-01-01	5.21234303022654
2002-01-01	5.36157449801595
2003-01-01	5.50845708002008
2004-01-01	5.62989667795683
2005-01-01	5.71489378738934
2006-01-01	5.70430224939943
2007-01-01	5.66279772550664
2008-01-01	5.59908729101547
2009-01-01	5.51791582069490
2010-01-01	5.42174910028982
2011-01-01	5.21427292069747
2012-01-01	4.99067082507262
2013-01-01	4.77287322199705
2014-01-01	4.59371206811071
2015-01-01	4.47127392276038
2016-01-01	4.44102602120246
2017-01-01	4.45965138326610