Year Percent 1974 0.2532 1976 2.621 1982 0.1808 1983 0.1633 1984 0.2931 1985 2.112 1986 1.296 1987 1.173 1988 3.695 1989 0.4001 1990 3.187 1991 3.524 1992 0.662 1993 3.99 1994 2.473 1995 1.184 1996 2.829 1997 5.769 1998 0.7747 1999 0.6494 2000 2.921 2001 2.414 2002 3.261 2003 4.044 2004 2.891 2005 3.31 2006 2.939 2007 3.141