Year Percent 1990 4.19353 1991 3.17128 1992 3.04297 1993 3.25266 1994 3.33811 1995 3.0096 1996 3.37884 1997 3.22941 1998 3.02882 1999 3.04757 2000 3.11043 2001 3.49688 2002 3.94503 2003 2.88741 2004 3.06161 2005 2.88586 2006 2.73103 2007 2.20601 2008 2.34209 2009 2.3011 2010 2.20434 2011 2.29232 2012 2.26771 2013 2.28529 2014 2.22036 2015 2.37528 2016 2.40425 2017 2.70397 2018 2.45711 2019 2.11308 2020 2.00927 2021 2.30025 2022 2.67553