Year	Percent
1973-01-01	35.071900000000000
1974-01-01	34.532500000000000
1975-01-01	35.350200000000000
1976-01-01	35.693000000000005
1977-01-01	37.359900000000000
1978-01-01	38.730200000000000
1979-01-01	41.380800000000000
1980-01-01	44.110300000000000
1981-01-01	47.041600000000000
1982-01-01	48.341200000000000
1983-01-01	51.751300000000000
1984-01-01	53.821900000000000
1985-01-01	55.322800000000000
1986-01-01	57.095500000000000
1987-01-01	59.831700000000000
1988-01-01	60.674100000000000
1989-01-01	63.211000000000006
1990-01-01	65.657400000000000
1991-01-01	65.824100000000000
1992-01-01	103.790000000000000
1993-01-01	143.134000000000000
1994-01-01	142.752000000000000
1995-01-01	143.342000000000000
1996-01-01	144.119000000000000
1997-01-01	141.129000000000000
1998-01-01	141.129000000000000
1999-01-01	141.129000000000000
2000-01-01	127.943000000000000
2001-01-01	107.225000000000000
2002-01-01	102.948000000000000
2003-01-01	97.718800000000000
2004-01-01	92.000000000000000
2005-01-01	90.800700000000000
2006-01-01	89.986400000000000
2007-01-01	87.266600000000000
2008-01-01	85.203400000000000
2009-01-01	81.045800000000000
2010-01-01	76.805900000000000
2011-01-01	76.853800000000000
2012-01-01	77.335900000000000
2013-01-01	77.131400000000000
2014-01-01	78.661000000000000
2015-01-01	80.917600000000000
2016-01-01	81.898400000000000