Annual Percent of Total
1960-01-01 45.7430225588349
1961-01-01 45.9630530485619
1962-01-01 46.2956189638273
1963-01-01 46.6352358852974
1964-01-01 46.8241986245778
1965-01-01 46.7899617098412
1966-01-01 46.7815864679170
1967-01-01 46.5665149063149
1968-01-01 46.2101785247752
1969-01-01 45.8422975748286
1970-01-01 45.5434056608521
1971-01-01 45.2608938756462
1972-01-01 45.0838283915184
1973-01-01 44.9462455109480
1974-01-01 44.6709148230136
1975-01-01 44.1134991617917
1976-01-01 43.6662901011540
1977-01-01 42.8963625124908
1978-01-01 41.9527612849910
1979-01-01 41.2290411013952
1980-01-01 41.0670959086578
1981-01-01 40.5204178363008
1982-01-01 40.7808877031428
1983-01-01 41.5031117837080
1984-01-01 42.1329035018578
1985-01-01 42.4284887108455
1986-01-01 43.3664581976375
1987-01-01 43.5942761117355
1988-01-01 43.5226810032680
1989-01-01 43.6877729840610
1990-01-01 44.2848495020027
1991-01-01 44.6271423550572
1992-01-01 45.3303142627182
1993-01-01 46.1107262791205
1994-01-01 46.5523408938268
1995-01-01 46.4761913343880
1996-01-01 46.2824467114798
1997-01-01 45.5555211280573
1998-01-01 44.3701483539162
1999-01-01 42.9794635244634
2000-01-01 41.5907897350587
2001-01-01 40.3384067032438
2002-01-01 39.3328341272694
2003-01-01 38.5361255364843
2004-01-01 37.8159720874625
2005-01-01 37.0659947049785
2006-01-01 36.2418122126932
2007-01-01 35.4293249106344
2008-01-01 34.6329734738114
2009-01-01 33.9161068452645
2010-01-01 33.3265961922573
2011-01-01 32.9205773108965
2012-01-01 32.4947184335298
2013-01-01 32.1090121530815
2014-01-01 31.8101028172085
2015-01-01 31.6021610251820
2016-01-01 31.3909266182687
2017-01-01 31.2784962899646