Year	Percent
1986-01-01	4.92949882455503
1987-01-01	4.43892609966996
1988-01-01	5.71721947693141
1989-01-01	7.14329712330147
1990-01-01	7.47748385290130
1991-01-01	9.84381922285350
1992-01-01	9.80355309934949
1993-01-01	9.02507911433582
1994-01-01	7.89354964506450
1995-01-01	6.53207876517482
1996-01-01	6.30675282258490
1997-01-01	6.90259032971879
1998-01-01	7.67086990958600
1999-01-01	6.76993354792351
2000-01-01	6.04975001677883
2001-01-01	5.46119602443523
2002-01-01	5.52632153508332
2003-01-01	5.18443225039661
2004-01-01	4.61022147848560
2005-01-01	4.19840884136671
2006-01-01	4.24500917836667
2007-01-01	3.95373147378986
2008-01-01	4.20392563056770
2009-01-01	5.94047960098946
2010-01-01	6.60353490856274
2011-01-01	6.34495099616624
2012-01-01	6.93164028268313
2013-01-01	6.60330542865552
2014-01-01	6.30295217802772
2015-01-01	6.08628422862196
2016-01-01	5.70708164937342
2017-01-01	5.41589697235756