Year	Percent of Total
1960-01-01	5.38397123167965
1961-01-01	5.29394688262967
1962-01-01	5.22715858489605
1963-01-01	5.17854858534903
1964-01-01	5.14213578735245
1965-01-01	5.11584915766852
1966-01-01	5.11978650965525
1967-01-01	5.13983653566260
1968-01-01	5.16683181341207
1969-01-01	5.18611258436138
1970-01-01	5.19107533264801
1971-01-01	5.20441545249419
1972-01-01	5.18629809812587
1973-01-01	5.15186344035583
1974-01-01	5.12204796599868
1975-01-01	5.10599232975869
1976-01-01	5.11744018261231
1977-01-01	5.13984500439526
1978-01-01	5.15593589651706
1979-01-01	5.13868916991333
1980-01-01	5.07734193847958
1981-01-01	5.02624285522265
1982-01-01	4.93917844360190
1983-01-01	4.83379303033628
1984-01-01	4.73186394076478
1985-01-01	4.64612751454859
1986-01-01	4.60082438450348
1987-01-01	4.56061507216944
1988-01-01	4.54100378371809
1989-01-01	4.56409393661275
1990-01-01	4.64134578345025
1991-01-01	4.75142824991071
1992-01-01	4.89585492803536
1993-01-01	5.05166279971104
1994-01-01	5.19391090943189
1995-01-01	5.31330373409766
1996-01-01	5.44637659500229
1997-01-01	5.55039580885853
1998-01-01	5.64068103947181
1999-01-01	5.73821488988562
2000-01-01	5.84989722065495
2001-01-01	6.06213354455790
2002-01-01	6.27830202071641
2003-01-01	6.46465484857186
2004-01-01	6.57431361924572
2005-01-01	6.58586424997242
2006-01-01	6.53459162857850
2007-01-01	6.41135384553312
2008-01-01	6.24402340174031
2009-01-01	6.06608371850365
2010-01-01	5.89824009126199
2011-01-01	5.81902411872502
2012-01-01	5.74652746484399
2013-01-01	5.69623132703475
2014-01-01	5.68903648877903
2015-01-01	5.73811196358632
2016-01-01	5.84971727571253
2017-01-01	6.01779337739907