Year	Percent
1960-01-01	1.6095899999999999
1961-01-01	1.8606900000000002
1962-01-01	2.2644200000000000
1963-01-01	3.7360300000000004
1964-01-01	5.7502900000000010
1965-01-01	6.0647900000000000
1966-01-01	6.3176300000000000
1967-01-01	6.4075600000000000
1968-01-01	6.8300700000000000
1969-01-01	7.3620500000000000
1970-01-01	7.7689300000000000
1971-01-01	8.2511500000000000
1972-01-01	7.7283700000000000
1973-01-01	8.0032800000000000
1974-01-01	9.2353500000000000
1975-01-01	10.3016000000000000
1976-01-01	11.5541000000000000
1977-01-01	13.5168000000000000
1978-01-01	15.1899000000000000
1979-01-01	14.8266000000000000
1980-01-01	14.3785000000000000
1981-01-01	15.2669000000000000
1982-01-01	12.9823000000000000
1983-01-01	11.8807000000000000
1984-01-01	5.6834300000000000
1985-01-01	5.8981600000000000
1986-01-01	10.5557000000000000
1987-01-01	13.3339000000000000
1988-01-01	15.0172000000000000
1989-01-01	17.1624000000000000
1990-01-01	19.9221000000000000
1991-01-01	24.3597000000000000
1992-01-01	31.0029000000000000
1993-01-01	39.1771000000000000
1994-01-01	44.8986000000000000
1995-01-01	45.2426000000000000
1996-01-01	47.6174000000000000
1997-01-01	52.2710000000000000
1998-01-01	58.4400000000000000
1999-01-01	63.0398000000000000
2000-01-01	59.7261000000000000
2001-01-01	55.1618000000000000
2002-01-01	50.4332000000000000
2003-01-01	46.8847000000000000
2004-01-01	42.3184000000000000
2005-01-01	41.6871000000000000
2006-01-01	37.6391000000000000
2007-01-01	35.3327000000000000
2008-01-01	33.7937000000000000
2009-01-01	35.5907000000000000
2010-01-01	35.8743000000000000
2011-01-01	37.4582000000000000
2012-01-01	40.1182000000000000
2013-01-01	42.8400000000000000
2014-01-01	46.8579000000000000
2015-01-01	54.2381000000000000
2016-01-01	60.5852000000000000