Year	Percent
1973-01-01	98.01290000000000
1974-01-01	98.15860000000000
1975-01-01	97.28490000000000
1976-01-01	92.97590000000000
1977-01-01	92.57950000000000
1978-01-01	94.85650000000000
1979-01-01	92.26010000000000
1980-01-01	90.66020000000000
1981-01-01	90.07370000000000
1982-01-01	87.82750000000000
1983-01-01	90.65660000000000
1984-01-01	96.44530000000000
1985-01-01	94.24390000000000
1986-01-01	92.40770000000000
1987-01-01	92.39760000000000
1988-01-01	90.52560000000000
1989-01-01	87.60920000000000
1990-01-01	84.08770000000000
1991-01-01	83.26250000000000
1992-01-01	83.91750000000000
1993-01-01	81.53540000000000
1994-01-01	73.93690000000000
1995-01-01	72.57380000000000
1996-01-01	78.38950000000000
1997-01-01	77.24300000000000
1998-01-01	71.23940000000000
1999-01-01	72.71170000000000
2000-01-01	87.11720000000000
2001-01-01	94.29680000000000
2002-01-01	87.28750000000000
2003-01-01	84.64390000000000
2004-01-01	93.14910000000000
2005-01-01	96.69940000000000
2006-01-01	96.45640000000000
2007-01-01	96.35050000000000
2008-01-01	96.96690000000000
2009-01-01	96.71590000000000
2010-01-01	96.15500000000000
2011-01-01	96.21750000000000
2012-01-01	96.02250000000000
2013-01-01	95.25299999999999
2014-01-01	91.26780000000000
2015-01-01	90.19840000000000
2016-01-01	88.80080000000000