Year	Percent of Total
1960-01-01	3.82703174641671
1961-01-01	3.80528669806186
1962-01-01	3.78273520853540
1963-01-01	3.74861934494962
1964-01-01	3.70941111722620
1965-01-01	3.66822379609498
1966-01-01	3.63050211761731
1967-01-01	3.59848875859364
1968-01-01	3.56564347614805
1969-01-01	3.54515449158945
1970-01-01	3.52886005705577
1971-01-01	3.54829408938011
1972-01-01	3.57981220657277
1973-01-01	3.61353630326095
1974-01-01	3.64656123574844
1975-01-01	3.66510177817252
1976-01-01	3.62470300301910
1977-01-01	3.56627354339025
1978-01-01	3.49450244528459
1979-01-01	3.41332512904659
1980-01-01	3.34350090159929
1981-01-01	3.37585019872616
1982-01-01	3.42908732764281
1983-01-01	3.50019427535293
1984-01-01	3.56408826575321
1985-01-01	3.62483008608972
1986-01-01	3.63258951738454
1987-01-01	3.60833172269220
1988-01-01	3.55147761150829
1989-01-01	3.48151284222410
1990-01-01	3.42346572391316
1991-01-01	3.48168249660787
1992-01-01	3.52418783185545
1993-01-01	3.53940226363264
1994-01-01	3.51893153865216
1995-01-01	3.47227582657918
1996-01-01	3.46864029807241
1997-01-01	3.44582460341215
1998-01-01	3.41017780502759
1999-01-01	3.36402863823735
2000-01-01	3.31966921782812
2001-01-01	3.38931724475296
2002-01-01	3.47137148941529
2003-01-01	3.53000731199730
2004-01-01	3.55636058403835
2005-01-01	3.55050094773897
2006-01-01	3.57309569276469
2007-01-01	3.57487722067054
2008-01-01	3.56054449410809
2009-01-01	3.55182563041922
2010-01-01	3.54985777188949
2011-01-01	3.56023543800642
2012-01-01	3.57648691998162
2013-01-01	3.61173814898420
2014-01-01	3.65387749189737
2015-01-01	3.70350600941223
2016-01-01	3.79736876611740
2017-01-01	3.89525593223251