Year	Percent
1960-01-01	35.174300000000000
1961-01-01	33.719700000000000
1962-01-01	35.240000000000000
1963-01-01	34.873600000000000
1964-01-01	35.015600000000000
1965-01-01	34.682700000000000
1966-01-01	35.884400000000000
1967-01-01	35.953800000000000
1968-01-01	35.725800000000000
1969-01-01	36.720000000000000
1970-01-01	38.763300000000000
1971-01-01	40.439200000000000
1972-01-01	40.089300000000000
1973-01-01	38.226100000000000
1974-01-01	35.266600000000000
1975-01-01	36.649000000000000
1976-01-01	37.040000000000000
1977-01-01	37.322300000000000
1978-01-01	37.955000000000000
1979-01-01	38.110500000000000
1980-01-01	38.597700000000000
1981-01-01	39.412000000000000
1982-01-01	40.387400000000000
1983-01-01	40.907700000000000
1984-01-01	41.818300000000000
1985-01-01	45.013000000000005
1986-01-01	46.901700000000000
1987-01-01	48.066200000000000
1988-01-01	49.787600000000000
1989-01-01	51.588900000000000
1990-01-01	52.524300000000000
1991-01-01	57.509500000000000
1992-01-01	59.767900000000000
1993-01-01	59.333400000000000
1994-01-01	56.424900000000000
1995-01-01	53.742900000000000
1996-01-01	52.692100000000000
1997-01-01	48.344700000000000
1998-01-01	45.841700000000000
1999-01-01	48.951000000000000
2000-01-01	48.728700000000000
2001-01-01	46.517200000000000
2002-01-01	48.511600000000000
2003-01-01	52.350600000000000
2004-01-01	54.031500000000000
2005-01-01	56.384700000000000
2006-01-01	58.505300000000000
2007-01-01	60.849400000000000
2008-01-01	65.063600000000000
2009-01-01	70.767500000000000
2010-01-01	70.602000000000000
2011-01-01	71.162500000000000
2012-01-01	72.053700000000000
2013-01-01	71.127400000000000
2014-01-01	72.519300000000000
2015-01-01	75.274900000000000
2016-01-01	76.746400000000000