Year % 1988 26.06424 1989 25.49622 1990 14.68104 1991 13.51651 1992 14.40344 1993 14.08887 1994 14.54027 1995 8.469366 1996 4.157885 1997 4.070841 1998 6.359293 1999 20.64743 2000 4.211875 2001 4.699732 2002 3.754065 2003 3.298512 2004 4.955564 2005 3.719069 2006 3.594573 2007 3.340821 2008 3.148012 2009 3.740263 2010 3.37444 2011 3.211788 2012 3.399374 2013 3.183203 2014 3.04756 2015 3.011401 2016 2.134678 2017 2.990922 2018 3.064476 2019 3.085244 2020 26.65311 2021 2.283862