Year	Percent
1960-01-01	52.3327000000000000
1961-01-01	50.1312000000000000
1962-01-01	50.5937000000000000
1963-01-01	51.3317000000000000
1964-01-01	49.7063000000000000
1965-01-01	48.3259000000000000
1966-01-01	48.4143000000000000
1967-01-01	49.8525000000000000
1968-01-01	52.7592000000000000
1969-01-01	52.7466000000000000
1970-01-01	49.7953000000000000
1971-01-01	49.6436000000000000
1972-01-01	50.3189000000000000
1973-01-01	51.3923000000000000
1974-01-01	51.0384000000000000
1975-01-01	47.6984000000000000
1976-01-01	45.9046000000000000
1977-01-01	45.1231000000000000
1978-01-01	45.8712000000000000
1979-01-01	47.6267000000000000
1980-01-01	46.9464000000000000
1981-01-01	48.9310000000000040
1982-01-01	49.2830000000000000
1983-01-01	46.1500000000000000
1984-01-01	43.6993000000000000
1985-01-01	43.2028000000000000
1986-01-01	43.3712000000000000
1987-01-01	44.7544000000000000
1988-01-01	44.7213000000000000
1989-01-01	45.0735000000000000
1990-01-01	26.4767000000000000
1991-01-01	6.3573300000000000
1992-01-01	6.3792800000000005
1993-01-01	5.0815700000000000
1994-01-01	4.5513100000000000
1995-01-01	6.0468600000000000
1996-01-01	7.8253200000000000
1997-01-01	8.4488200000000000
1998-01-01	4.1090599999999995
1999-01-01	0.0663200000000000
2000-01-01	0.0663200000000000
2001-01-01	40.1168000000000000
2002-01-01	39.9305000000000000
2003-01-01	40.0818000000000000
2004-01-01	39.4230000000000000
2005-01-01	40.9662000000000000
2006-01-01	43.4375000000000000
2007-01-01	45.7732000000000000
2008-01-01	50.3071000000000000
2009-01-01	55.2762000000000000
2010-01-01	55.0856000000000000
2011-01-01	57.6898000000000000
2012-01-01	60.1453000000000000
2013-01-01	61.4555000000000000
2014-01-01	62.5155000000000000
2015-01-01	62.7234000000000000
2016-01-01	64.8963000000000000