Year Number 1995 1.5515759049867763 1996 1.1338701412242733 1997 1.2291336515382378 1998 1.0454231635555093 1999 1.185047007813881 2000 0.9621381461050196 2001 1.1721729702306944 2002 0.8643154105013251 2003 1.089902871045402 2004 1.7799099153022766 2005 1.9854940926713136 2006 1.9474394913570237 2007 1.958375532530394 2008 2.4509440731530057 2009 2.0453128922210806 2010 2.0423446042892914 2011 1.5771275521104142 2012 1.7553833629721207 2013 1.7283572367939601 2014 1.7032734802678968 2015 1.3194177862596719 2016 1.3858854463177825 2017 1.1826542914548444 2018 1.2113504503159902 2019 0.6270523232605146 2020 0.6372006318041671 2021 0.6681608405160032