Year	Percent
1980-01-01	3.917610000000000
1981-01-01	7.644819999999999
1982-01-01	11.412900000000000
1983-01-01	13.159500000000000
1984-01-01	16.930400000000000
1985-01-01	19.794200000000000
1986-01-01	25.201500000000000
1987-01-01	28.698300000000000
1988-01-01	32.809700000000000
1989-01-01	36.271700000000000
1990-01-01	33.058800000000000
1991-01-01	38.387000000000000
1992-01-01	34.847600000000000
1993-01-01	40.378400000000000
1994-01-01	38.932300000000000
1995-01-01	38.871800000000000
1996-01-01	41.385900000000000
1997-01-01	40.950300000000000
1998-01-01	67.556900000000000
1999-01-01	67.556900000000000
2000-01-01	67.556900000000000
2001-01-01	67.556900000000000
2002-01-01	67.556900000000000
2003-01-01	67.556900000000000
2004-01-01	60.470400000000000
2005-01-01	53.685500000000000
2006-01-01	50.057200000000000
2007-01-01	36.502200000000000
2008-01-01	28.693100000000000
2009-01-01	17.432900000000000
2010-01-01	19.799100000000000
2011-01-01	16.664600000000000
2012-01-01	18.147600000000000
2013-01-01	19.349800000000000
2014-01-01	19.270700000000000
2015-01-01	20.217000000000000
2016-01-01	22.352200000000000