Year	Percent
1980-01-01	3.50998000000000000
1981-01-01	5.67016000000000000
1982-01-01	7.57256000000000000
1983-01-01	12.18150000000000000
1984-01-01	15.23800000000000000
1985-01-01	21.91990000000000000
1986-01-01	25.95560000000000000
1987-01-01	23.61870000000000000
1988-01-01	19.50920000000000000
1989-01-01	18.57520000000000000
1990-01-01	16.56910000000000000
1991-01-01	17.26570000000000000
1992-01-01	16.47250000000000000
1993-01-01	20.79720000000000000
1994-01-01	18.91320000000000000
1995-01-01	16.19400000000000300
1996-01-01	11.58120000000000000
1997-01-01	8.29152000000000000
1998-01-01	7.60643999999999900
1999-01-01	6.33139000000000000
2000-01-01	4.79758000000000000
2001-01-01	7.55810000000000000
2002-01-01	5.28061000000000000
2003-01-01	2.10094000000000000
2004-01-01	0.43811500000000000
2005-01-01	0.29634699999999997
2006-01-01	0.27007200000000000
2007-01-01	0.60594200000000000
2008-01-01	10.37500000000000000
2009-01-01	5.62950000000000000
2010-01-01	7.09583999999999900
2011-01-01	6.16345000000000000
2012-01-01	7.24236999999999900
2013-01-01	8.11571000000000000
2014-01-01	9.27415000000000000
2015-01-01	6.87942000000000000
2016-01-01	6.14668000000000000