Year % 1996 3.452945 1997 3.452945 1998 3.452945 1999 3.452945 2000 3.452945 2001 2.971282 2002 2.971282 2003 2.971282 2004 2.601649 2005 4.149299 2006 3.170393 2007 6.034483 2008 3.170393 2010 1.728691 2011 1.712274 2012 3.804426 2013 3.890671 2015 3.895012 2019 3.675694 2021 2.703964