Year Percent 1980 5.11541 1981 6.89145 1982 12.21996 1983 12.63184 1984 9.26166 1985 9.99114 1986 10.28977 1987 12.28407 1988 13.57066 1989 15.08696 1990 13.96232 1991 14.6141 1992 14.95898 1993 13.73454 1994 13.00458 1995 13.59639 1996 13.45218 1997 14.4455 1998 14.20024 1999 14.09157 2000 13.79611 2001 9.82631 2002 9.50793 2003 9.4207 2004 10.48944 2005 11.56937 2006 11.75644 2007 12.14745 2008 11.57888 2009 9.10067 2010 8.84763 2011 12.07813 2014 19.46369