Year	Percent
1976-01-01	2.7031500000000000
1977-01-01	2.5794300000000000
1978-01-01	2.2601000000000000
1979-01-01	2.2937200000000000
1980-01-01	2.5296400000000000
1981-01-01	2.7517200000000000
1982-01-01	2.5520000000000000
1983-01-01	2.4709900000000000
1984-01-01	2.1010600000000000
1985-01-01	1.8874000000000000
1986-01-01	1.6147400000000000
1987-01-01	1.7225000000000000
1988-01-01	2.1801200000000000
1989-01-01	2.7505599999999997
1990-01-01	3.7294099999999997
1991-01-01	4.1593900000000000
1992-01-01	3.9577500000000000
1993-01-01	10.9747000000000000
1994-01-01	25.6326000000000000
1995-01-01	38.0025000000000000
1996-01-01	41.2365000000000000
1997-01-01	44.0906000000000000
1998-01-01	43.6258000000000000
1999-01-01	39.8915000000000000
2000-01-01	42.9219000000000000
2001-01-01	46.2073000000000000
2002-01-01	48.9752000000000000
2003-01-01	50.9798000000000000
2004-01-01	52.8868000000000000
2005-01-01	54.2758000000000000
2006-01-01	56.3391000000000000
2007-01-01	58.3079000000000000
2008-01-01	61.6541000000000000
2009-01-01	68.0563000000000000
2010-01-01	73.6495000000000000
2011-01-01	78.1204000000000000
2012-01-01	81.4883000000000000
2013-01-01	81.0781000000000000
2014-01-01	83.8988000000000000
2015-01-01	85.0917000000000000
2016-01-01	85.5610000000000000