Year	Percent
1980-01-01	16.9495
1981-01-01	21.0157
1982-01-01	23.9336
1983-01-01	31.1996
1984-01-01	29.2476
1985-01-01	33.4503
1986-01-01	30.9548
1987-01-01	11.4565
1988-01-01	14.3592
1989-01-01	17.1306
1990-01-01	17.8215
1991-01-01	20.1880
1992-01-01	17.8467
1993-01-01	14.8876
1994-01-01	15.3008
1995-01-01	22.7547
1996-01-01	27.4783
1997-01-01	22.5344
1998-01-01	27.8937
1999-01-01	31.7133
2000-01-01	38.6935
2001-01-01	39.1444
2002-01-01	38.7473
2003-01-01	38.6415
2004-01-01	50.7521
2005-01-01	56.2750
2006-01-01	57.1153
2007-01-01	58.2191
2008-01-01	55.3650
2009-01-01	59.5338
2010-01-01	66.7509
2011-01-01	60.4201
2012-01-01	58.1815
2013-01-01	25.7985
2014-01-01	50.6165
2015-01-01	49.3933
2016-01-01	48.5444