Year Number 1996 1.07101774215698 1998 1.08732557296753 2000 1.2795318365097 2002 0.955541908740997 2003 0.826347827911377 2004 0.890613675117493 2005 0.93814343214035 2006 0.810453712940216 2007 0.730122447013855 2008 0.774532914161682 2009 0.859580457210541 2010 0.993692219257355 2011 1.10362148284912 2012 1.18402600288391 2013 1.13482463359833 2014 0.956470131874084 2015 0.89498245716095 2016 0.959943354129791 2017 0.976761102676392 2018 0.84756064414978 2019 0.801466107368469 2020 0.830237448215485 2021 0.850836753845215 2022 0.883432567119598