Year	Percent of Total
1960-01-01	5.41051162062912
1961-01-01	5.39059256183641
1962-01-01	5.40519231787409
1963-01-01	5.43491494716101
1964-01-01	5.45608493848696
1965-01-01	5.45776254202650
1966-01-01	5.40367648380083
1967-01-01	5.33713781956509
1968-01-01	5.27081703593342
1969-01-01	5.22010065472723
1970-01-01	5.19320672668718
1971-01-01	5.18152527094256
1972-01-01	5.17821996553444
1973-01-01	5.18164980704709
1974-01-01	5.18837904177424
1975-01-01	5.19685189585892
1976-01-01	5.21799787042027
1977-01-01	5.23982156360609
1978-01-01	5.26146548204600
1979-01-01	5.28202183615950
1980-01-01	5.30124319391147
1981-01-01	5.32996213618179
1982-01-01	5.35477711620714
1983-01-01	5.37573734690202
1984-01-01	5.39093711314341
1985-01-01	5.39986207352169
1986-01-01	5.41353571366327
1987-01-01	5.41739178351834
1988-01-01	5.42343967142384
1989-01-01	5.44827111409442
1990-01-01	5.50262170367160
1991-01-01	5.65727075307036
1992-01-01	5.83705976725822
1993-01-01	6.03646307369960
1994-01-01	6.24232032465186
1995-01-01	6.44531752939420
1996-01-01	6.57742572669286
1997-01-01	6.69696909934269
1998-01-01	6.81251347156787
1999-01-01	6.93663065834375
2000-01-01	7.07457150453079
2001-01-01	7.33190537559473
2002-01-01	7.61047749155266
2003-01-01	7.90631966197419
2004-01-01	8.21132261608195
2005-01-01	8.52178454061943
2006-01-01	8.92771608578114
2007-01-01	9.34502946023142
2008-01-01	9.77530467290469
2009-01-01	10.21823478086230
2010-01-01	10.67258397735100
2011-01-01	11.05383305673810
2012-01-01	11.41861461439380
2013-01-01	11.77179135985270
2014-01-01	12.13698419083980
2015-01-01	12.53670444065580
2016-01-01	12.83391449000600
2017-01-01	13.18752011390400