Year	Percent
1981-01-01	12.41326137239800
1982-01-01	12.13991769547340
1983-01-01	11.56752438340690
1984-01-01	11.24999999999970
1985-01-01	10.30544066982950
1986-01-01	7.43333333333314
1987-01-01	8.15234253800876
1988-01-01	8.75549685086139
1989-01-01	8.27501608751591
1990-01-01	7.72532188841208
1991-01-01	8.96562265214311
1992-01-01	9.52347719108987
1993-01-01	9.67934658067928
1994-01-01	28.81438943067320
1995-01-01	12.28859126014260
1996-01-01	7.27288773042940
1997-01-01	8.16902144106960
1998-01-01	6.66139865665754
1999-01-01	4.24955255897249
2000-01-01	4.19928825622804
2001-01-01	5.16723996083341
2002-01-01	5.03282275711197
2003-01-01	6.15429081789710
2004-01-01	4.17816000119791
2005-01-01	7.79749781786440
2006-01-01	6.53784395299603
2007-01-01	6.78669789053908
2008-01-01	10.46007313547060
2009-01-01	7.32200074871784
2010-01-01	4.06353897303290
2011-01-01	5.68631959575963
2012-01-01	6.57589970757695
2013-01-01	4.97576820829645
2014-01-01	4.40380271714362
2015-01-01	4.08955435598132
2016-01-01	5.62922705547694
2017-01-01	5.31871605228926