Year	Percent
1973-01-01	35.761900000000000
1974-01-01	33.381100000000000
1975-01-01	33.896500000000000
1976-01-01	31.580200000000000
1977-01-01	30.256500000000000
1978-01-01	28.062300000000000
1979-01-01	24.745800000000000
1980-01-01	22.454700000000000
1981-01-01	24.089600000000000
1982-01-01	23.634900000000000
1983-01-01	23.172400000000000
1984-01-01	23.073100000000000
1985-01-01	22.441800000000000
1986-01-01	22.763800000000000
1987-01-01	23.393700000000000
1988-01-01	25.287300000000000
1989-01-01	24.688000000000002
1990-01-01	29.169500000000000
1991-01-01	33.561300000000000
1992-01-01	35.439600000000000
1993-01-01	39.830200000000000
1994-01-01	42.921600000000000
1995-01-01	44.964300000000000
1996-01-01	46.808800000000000
1997-01-01	51.493700000000000
1998-01-01	56.683500000000000
1999-01-01	56.148400000000000
2000-01-01	59.603700000000000
2001-01-01	63.389400000000000
2002-01-01	62.747400000000000
2003-01-01	64.559800000000000
2004-01-01	64.366100000000000
2005-01-01	65.630200000000000
2006-01-01	73.100000000000000
2007-01-01	78.402400000000000
2008-01-01	86.818800000000000
2009-01-01	95.391200000000000
2010-01-01	96.995800000000000
2011-01-01	100.232999999999990
2012-01-01	94.844600000000000
2013-01-01	94.354400000000000
2014-01-01	95.228600000000000
2015-01-01	94.727000000000000
2016-01-01	94.595200000000000