Year Percent 1981-01-01 11.33651544151050 1982-01-01 12.31245087077360 1983-01-01 11.12664412214300 1984-01-01 11.37332209029370 1985-01-01 10.42384023038870 1986-01-01 6.80905593895123 1987-01-01 7.02827195245956 1988-01-01 6.93068617206519 1989-01-01 8.04615863487319 1990-01-01 6.80119760762573 1991-01-01 8.81964099733880 1992-01-01 9.52347719108987 1993-01-01 8.52787695688003 1994-01-01 32.29366685695510 1995-01-01 14.37880865164200 1996-01-01 7.41137173526642 1997-01-01 5.57225711125332 1998-01-01 6.20801608663320 1999-01-01 3.94327409481390 2000-01-01 4.16540442290281 2001-01-01 4.93944977668384 2002-01-01 3.89570525758491 2003-01-01 5.30238773219937 2004-01-01 4.47499289078105 2005-01-01 8.51673434919865 2006-01-01 6.69526465773351 2007-01-01 7.60315916084459 2008-01-01 11.30510988270190 2009-01-01 4.56158154742791 2010-01-01 4.69889064976229 2011-01-01 6.76227957314765 2012-01-01 6.31474450315182 2013-01-01 5.51827136955831 2014-01-01 4.48576293622033 2015-01-01 4.02917184654451 2016-01-01 4.77744170418787 2017-01-01 5.26421655571573