Year	Percent
1960-01-01	16.11390000000000
1961-01-01	14.11320000000000
1962-01-01	16.12700000000000
1963-01-01	17.49030000000000
1964-01-01	17.71420000000000
1965-01-01	17.75810000000000
1966-01-01	28.41610000000000
1967-01-01	30.32000000000000
1968-01-01	26.55490000000000
1969-01-01	26.55490000000000
1970-01-01	26.55490000000000
1971-01-01	26.55490000000000
1972-01-01	26.55490000000000
1973-01-01	26.55490000000000
1974-01-01	26.55490000000000
1975-01-01	34.16190000000000
1976-01-01	30.25280000000000
1977-01-01	32.71640000000000
1978-01-01	34.08190000000000
1979-01-01	41.58170000000000
1980-01-01	46.93610000000000
1981-01-01	47.60250000000000
1982-01-01	49.40910000000000
1983-01-01	55.55260000000000
1984-01-01	61.61600000000001
1985-01-01	65.07330000000000
1986-01-01	60.76830000000000
1987-01-01	64.15560000000000
1988-01-01	65.89870000000000
1989-01-01	73.65180000000000
1990-01-01	67.17760000000000
1991-01-01	67.56390000000000
1992-01-01	58.78020000000000
1993-01-01	63.03450000000000
1994-01-01	65.57950000000000
1995-01-01	68.69540000000000
1996-01-01	74.41040000000000
1997-01-01	73.84380000000000
1998-01-01	72.40460000000000
1999-01-01	74.75670000000000
2000-01-01	75.83440000000000
2001-01-01	74.65570000000000
2002-01-01	71.72550000000000
2003-01-01	69.45350000000000
2004-01-01	68.75630000000000
2005-01-01	77.19910000000000
2006-01-01	82.32820000000000
2007-01-01	85.19980000000000
2008-01-01	80.04810000000000
2009-01-01	74.21690000000000
2010-01-01	70.26200000000000
2011-01-01	69.85360000000000
2012-01-01	70.33600000000000
2013-01-01	69.54620000000000
2014-01-01	69.20570000000000
2015-01-01	68.23240000000000
2016-01-01	70.89660000000000