Year	Percent
1973-01-01	4.585920000000000
1974-01-01	5.955960000000000
1975-01-01	9.442290000000000
1976-01-01	13.502900000000000
1977-01-01	16.062500000000000
1978-01-01	15.877500000000000
1979-01-01	15.862300000000000
1980-01-01	15.123700000000000
1981-01-01	14.476100000000000
1982-01-01	14.872300000000000
1983-01-01	14.889200000000000
1984-01-01	14.530999999999999
1985-01-01	13.790400000000000
1986-01-01	14.629600000000000
1987-01-01	14.822200000000000
1988-01-01	14.968900000000000
1989-01-01	16.214100000000000
1990-01-01	18.268600000000000
1991-01-01	16.444300000000000
1992-01-01	13.173900000000000
1993-01-01	11.638400000000000
1994-01-01	10.873900000000000
1995-01-01	9.083900000000000
1996-01-01	8.517700000000000
1997-01-01	10.680700000000000
1998-01-01	12.617400000000000
1999-01-01	11.628900000000000
2000-01-01	11.964600000000000
2001-01-01	13.446400000000000
2002-01-01	15.264900000000000
2003-01-01	16.237600000000000
2004-01-01	16.919100000000000
2005-01-01	18.011000000000000
2006-01-01	20.012600000000000
2007-01-01	19.577500000000000
2008-01-01	19.765000000000000
2009-01-01	19.702400000000000
2010-01-01	19.025800000000000
2011-01-01	21.214700000000000
2012-01-01	23.618400000000000
2013-01-01	28.001500000000000
2014-01-01	33.041700000000000
2015-01-01	35.130300000000000
2016-01-01	33.716800000000000