Year	Percent
1979-01-01	5.21753315833333
1980-01-01	5.12680480833333
1981-01-01	4.86150627500000
1982-01-01	6.41904529166667
1983-01-01	9.82447187500000
1984-01-01	8.78690590000000
1985-01-01	8.03267061666666
1986-01-01	7.75380390000000
1987-01-01	7.85359509166667
1988-01-01	6.84841393333333
1989-01-01	5.77182566666667
1990-01-01	6.81286125833333
1991-01-01	10.00555685833330
1992-01-01	11.45123950833330
1993-01-01	11.64452849166670
1994-01-01	10.11751199166670
1995-01-01	8.86719383333334
1996-01-01	8.83019267500000
1997-01-01	8.71217933333333
1998-01-01	8.07008201666667
1999-01-01	7.14791323333333
2000-01-01	6.56120444166667
2001-01-01	7.08861050000000
2002-01-01	6.64632894166667
2003-01-01	5.99372733333333
2004-01-01	5.37442750833333
2005-01-01	4.97630870833333
2006-01-01	4.75455573333333
2007-01-01	4.12269395833333
2008-01-01	4.04636766666667
2009-01-01	5.83777195000000
2010-01-01	5.19258250000000
2011-01-01	5.03206465833333
2012-01-01	5.26944447500000
2013-01-01	5.87300263333333
2014-01-01	6.14529674166667
2015-01-01	6.22966214166667
2016-01-01	5.82110770833333
2017-01-01	5.70854899166667