Year	Percent of Total
1960-01-01	43.1446023150642
1961-01-01	43.3237359971689
1962-01-01	43.4287431375353
1963-01-01	43.4972177443548
1964-01-01	43.5625830054449
1965-01-01	43.6356785761107
1966-01-01	43.7973809240860
1967-01-01	43.9147762994322
1968-01-01	44.0110470820713
1969-01-01	44.1090015265300
1970-01-01	44.2251193332042
1971-01-01	44.2470849832011
1972-01-01	44.2529857392068
1973-01-01	44.2502526401548
1974-01-01	44.2323454308863
1975-01-01	44.2002056078968
1976-01-01	44.0745436562725
1977-01-01	43.9016624220504
1978-01-01	43.7298268170842
1979-01-01	43.6095782167913
1980-01-01	43.5573623346983
1981-01-01	43.2341908354098
1982-01-01	42.9644607931876
1983-01-01	42.7286352233544
1984-01-01	42.4724791022675
1985-01-01	42.1693949897321
1986-01-01	42.2456624884311
1987-01-01	42.1936077259140
1988-01-01	42.1200598631904
1989-01-01	42.0648486691753
1990-01-01	41.9832465793237
1991-01-01	42.1374084359048
1992-01-01	42.2571699722300
1993-01-01	42.2614538277412
1994-01-01	42.0852554380979
1995-01-01	41.7243773578138
1996-01-01	40.8513976212522
1997-01-01	39.9802036094704
1998-01-01	39.2268199434899
1999-01-01	38.6481230344953
2000-01-01	38.1983905847687
2001-01-01	37.2454983178424
2002-01-01	36.3504932004060
2003-01-01	35.4986572561920
2004-01-01	34.6661377276314
2005-01-01	33.8482561489428
2006-01-01	32.9936719385119
2007-01-01	32.1167719609043
2008-01-01	31.2641413496978
2009-01-01	30.4836353494396
2010-01-01	29.7868172875666
2011-01-01	28.8253850659501
2012-01-01	27.9669296502137
2013-01-01	27.2132295786375
2014-01-01	26.5609345920595
2015-01-01	25.9985250883286
2016-01-01	25.5354936364329
2017-01-01	25.1647319179095