Year	Percent
1988-01-01	35.5696
1989-01-01	34.3414
1990-01-01	33.9474
1991-01-01	33.0394
1992-01-01	30.7754
1993-01-01	28.0468
1994-01-01	28.9407
1995-01-01	28.7001
1996-01-01	31.1994
1997-01-01	28.3114
1998-01-01	34.7280
1999-01-01	40.1014
2000-01-01	37.6433
2001-01-01	40.4668
2002-01-01	43.3377
2003-01-01	52.4554
2004-01-01	51.6284
2005-01-01	49.2753
2006-01-01	58.0953
2007-01-01	70.6033
2008-01-01	60.3847
2009-01-01	76.4846
2010-01-01	65.7036
2011-01-01	55.7236
2012-01-01	56.4526
2013-01-01	50.9289
2014-01-01	54.2226
2015-01-01	58.1768
2016-01-01	55.6392