Year	Percent
1960-01-01	13.622400000000000
1961-01-01	12.260600000000000
1962-01-01	12.874300000000000
1963-01-01	17.623600000000000
1964-01-01	19.159400000000000
1965-01-01	19.603800000000000
1966-01-01	19.682700000000000
1967-01-01	20.895100000000000
1968-01-01	22.341200000000000
1969-01-01	23.190900000000000
1970-01-01	22.893400000000000
1971-01-01	24.896500000000000
1972-01-01	28.855600000000000
1973-01-01	31.535999999999998
1974-01-01	29.846800000000000
1975-01-01	32.481000000000000
1976-01-01	34.949000000000000
1977-01-01	39.161300000000000
1978-01-01	40.236800000000000
1979-01-01	42.856900000000000
1980-01-01	45.017400000000000
1981-01-01	49.653200000000000
1982-01-01	66.311100000000000
1983-01-01	80.402600000000000
1984-01-01	80.704800000000000
1985-01-01	82.221200000000000
1986-01-01	88.734400000000000
1987-01-01	56.453800000000000
1988-01-01	59.400200000000000
1989-01-01	31.228300000000000
1990-01-01	31.365300000000000
1991-01-01	21.407800000000000
1992-01-01	29.767200000000000
1993-01-01	36.029600000000000
1994-01-01	29.522600000000000
1995-01-01	30.482400000000000
1996-01-01	34.322200000000000
1997-01-01	36.749400000000000
1998-01-01	40.128900000000000
1999-01-01	38.172500000000000
2000-01-01	39.679500000000000
2001-01-01	44.024800000000000
2002-01-01	48.527600000000000
2003-01-01	50.738300000000000
2004-01-01	51.302500000000000
2005-01-01	52.233500000000000
2006-01-01	52.369500000000000
2007-01-01	51.126400000000000
2008-01-01	50.452800000000000
2009-01-01	52.379700000000000
2010-01-01	52.505400000000000
2011-01-01	52.612800000000000
2012-01-01	53.100600000000000
2013-01-01	55.477700000000000
2014-01-01	55.502700000000000
2015-01-01	54.356800000000000
2016-01-01	52.906900000000000