Year Number 1996 1.42448508739471 1998 1.41288626194 2000 1.41334688663483 2002 1.42574501037598 2003 1.45393228530884 2004 1.69253361225128 2005 1.58643817901611 2006 1.51800584793091 2007 1.50381481647491 2008 1.51682984828949 2009 1.55331099033356 2010 1.58491122722626 2011 1.58480751514435 2012 1.64012205600739 2013 1.628098487854 2014 1.55951905250549 2015 1.55852127075195 2016 1.53184378147125 2017 1.55687963962555 2018 1.59192168712616 2019 1.49498355388641 2020 1.53520882129669 2021 1.54160118103027 2022 1.61555957794189