Year	Percent
1986-01-01	20.5864683287634
1987-01-01	21.5048836386155
1988-01-01	23.8752647008727
1989-01-01	25.1462322065930
1990-01-01	25.6715310880738
1991-01-01	26.0935141425221
1992-01-01	26.7703564101002
1993-01-01	26.7965192974679
1994-01-01	26.3247753812476
1995-01-01	25.8577971013466
1996-01-01	25.5159882400397
1997-01-01	25.6877376805276
1998-01-01	26.4248141938654
1999-01-01	26.5648620214212
2000-01-01	26.4431884617564
2001-01-01	26.1879535663596
2002-01-01	25.4709484326876
2003-01-01	26.2411846848047
2004-01-01	25.5208137290483
2005-01-01	24.9748446293393
2006-01-01	24.4613774359385
2007-01-01	24.4547283614298
2008-01-01	24.9436092647138
2009-01-01	25.5798466010637
2010-01-01	25.8666511615420
2011-01-01	25.7798742036231
2012-01-01	26.4429889688689
2013-01-01	26.4997209592821
2014-01-01	25.7055985736983
2015-01-01	25.6754555459438
2016-01-01	24.6758075548916
2017-01-01	23.7738828836806