Year	Percent
1980-01-01	5.11
1981-01-01	7.89
1982-01-01	9.10
1983-01-01	8.22
1984-01-01	9.26
1985-01-01	11.42
1986-01-01	15.94
1987-01-01	16.74
1988-01-01	16.73
1989-01-01	18.86
1990-01-01	19.31
1991-01-01	22.28
1992-01-01	24.86
1993-01-01	29.83
1994-01-01	30.04
1995-01-01	36.70
1996-01-01	43.56
1997-01-01	51.98
1998-01-01	60.96
1999-01-01	71.22
2000-01-01	68.36
2001-01-01	66.45
2002-01-01	59.08
2003-01-01	65.62
2004-01-01	67.81
2005-01-01	70.20
2006-01-01	78.09
2007-01-01	87.09
2008-01-01	68.97
2009-01-01	82.46
2010-01-01	85.71
2011-01-01	81.72
2012-01-01	89.10
2013-01-01	100.20
2014-01-01	102.42
2015-01-01	97.97
2016-01-01	101.31