Year	Percent
1960-01-01	15.201200000000000
1961-01-01	15.558100000000000
1962-01-01	15.258300000000000
1963-01-01	13.566300000000000
1964-01-01	14.151700000000000
1965-01-01	16.837700000000000
1966-01-01	16.723600000000000
1967-01-01	16.820800000000000
1968-01-01	17.775500000000000
1969-01-01	20.839100000000000
1970-01-01	23.145900000000000
1971-01-01	23.813000000000002
1972-01-01	25.696300000000000
1973-01-01	27.772900000000000
1974-01-01	26.624900000000000
1975-01-01	26.556600000000000
1976-01-01	26.689000000000000
1977-01-01	23.105800000000000
1978-01-01	19.169900000000000
1979-01-01	19.813400000000000
1980-01-01	21.044300000000000
1981-01-01	23.155300000000000
1982-01-01	27.699900000000000
1983-01-01	29.505700000000000
1984-01-01	28.516100000000000
1985-01-01	25.939200000000000
1986-01-01	25.589400000000000
1987-01-01	28.869400000000000
1988-01-01	32.621500000000000
1989-01-01	36.865400000000000
1990-01-01	28.521400000000000
1991-01-01	23.208800000000000
1992-01-01	17.981700000000000
1993-01-01	16.534700000000000
1994-01-01	17.871800000000000
1995-01-01	17.781400000000000
1996-01-01	20.440900000000000
1997-01-01	19.251600000000000
1998-01-01	21.012900000000000
1999-01-01	23.590000000000000
2000-01-01	24.635700000000000
2001-01-01	19.257700000000000
2002-01-01	13.633600000000000
2003-01-01	16.032000000000000
2004-01-01	18.570000000000000
2005-01-01	20.355000000000000
2006-01-01	21.978000000000000
2007-01-01	23.550900000000000
2008-01-01	27.916300000000000
2009-01-01	28.341800000000000
2010-01-01	26.740200000000000
2011-01-01	25.605800000000000
2012-01-01	27.024500000000000
2013-01-01	28.239500000000000
2014-01-01	28.660300000000000
2015-01-01	28.307700000000000
2016-01-01	29.993500000000000