Annual Percent of Total
1960-01-01 56.6237483831338
1961-01-01 55.4881826856036
1962-01-01 54.4302864250438
1963-01-01 53.4957648733293
1964-01-01 52.7458427716733
1965-01-01 52.2168488451650
1966-01-01 51.7783682930966
1967-01-01 51.5932305973957
1968-01-01 51.6210887239182
1969-01-01 51.7923747661925
1970-01-01 52.0636298497170
1971-01-01 52.4702386728983
1972-01-01 52.8557881331236
1973-01-01 53.2478845864319
1974-01-01 53.7047231806912
1975-01-01 54.2569803137392
1976-01-01 54.8113146203952
1977-01-01 55.4466189460859
1978-01-01 56.1161488069954
1979-01-01 56.7363872405027
1980-01-01 57.2582907525684
1981-01-01 57.6457257122003
1982-01-01 57.9212782764964
1983-01-01 58.0813099478166
1984-01-01 58.1660941391618
1985-01-01 58.2122538194579
1986-01-01 58.0514710122505
1987-01-01 57.9181442247368
1988-01-01 57.7962609348960
1989-01-01 57.6659118507338
1990-01-01 57.5348568109420
1991-01-01 57.2389866936855
1992-01-01 57.0181462888081
1993-01-01 56.8863072723380
1994-01-01 56.8642876727698
1995-01-01 56.9610259287657
1996-01-01 57.3158972289702
1997-01-01 57.7576090638506
1998-01-01 58.2747500247035
1999-01-01 58.8694930745512
2000-01-01 59.5530367722759
2001-01-01 60.1409143209493
2002-01-01 60.8180597180308
2003-01-01 61.6123156997360
2004-01-01 62.4965734927983
2005-01-01 63.4006911797737
2006-01-01 64.0009518738065
2007-01-01 64.5743893697541
2008-01-01 65.0487411003642
2009-01-01 65.3841825755447
2010-01-01 65.5791405071282
2011-01-01 65.5624949038436
2012-01-01 65.4383862449563
2013-01-01 65.2281885665385
2014-01-01 64.9515998258571
2015-01-01 64.6215322703426
2016-01-01 64.1285859979643
2017-01-01 63.6672044560924