Year Percent 1992 2.40023 1993 5.00047 1994 1.94658 1995 2.7369 1996 2.25423 1997 2.32405 1998 2.41236 1999 2.62511 2000 2.26786 2001 2.31206 2002 2.24331 2003 2.42636 2004 2.62948 2005 2.29907 2006 3.41776 2007 2.86419 2008 3.29121 2009 3.32542 2010 2.791 2011 4.67014 2012 4.65862 2013 4.54092 2014 4.55501 2015 5.46769 2016 3.69046 2017 3.9374