Year	Percent
1990-01-01	1.335
1991-01-01	1.090
1992-01-01	1.480
1993-01-01	1.080
1994-01-01	0.965
1995-01-01	0.985
1996-01-01	1.265
1997-01-01	1.580
1998-01-01	2.065
1999-01-01	2.570
2000-01-01	2.870
2001-01-01	2.380
2002-01-01	2.330
2003-01-01	2.270
2004-01-01	2.260
2005-01-01	2.260
2006-01-01	2.280
2007-01-01	2.160
2008-01-01	2.600
2009-01-01	2.690
2010-01-01	2.920
2011-01-01	2.330
2012-01-01	2.470
2013-01-01	2.690
2014-01-01	2.570
2015-01-01	2.120