Year % 1980 5.039999999 1981 5.039999999 1982 7.199999999 1983 7.199999999 1984 7.199999999 1985 7.919999999 1986 7.92 1987 7.92 1988 9 1989 11.34 1990 9.36 1991 8.64 1992 8.64 1993 10.98 1994 10.98 1995 12.06 1996 10.08 1997 8.64 1998 6.39 1999 5.85 2000 5.85 2001 5.85 2002 5.31 2003 5.31 2004 5.58 2005 5.58 2006 6.12 2007 7.47 2008 5.31 2009 5.31 2010 5.81 2011 6.56 2012 6 2013 6 2014 5.6 2015 4.35 2016 4.35 2017 4.35 2018 4.35 2019 4.35 2020 4.35 2021 4.35 2022 4.35 2023 4.35