Year Number 1996 1.73164963722229 1998 1.80350625514984 2000 1.84726524353027 2002 1.88022816181183 2003 1.93046128749847 2004 1.84377062320709 2005 1.67952907085419 2006 1.82738518714905 2007 1.86356592178345 2008 1.77165818214417 2009 1.66273927688599 2010 1.81252110004425 2011 1.60288524627686 2012 1.56018972396851 2013 1.57191109657288 2014 1.55362224578857 2015 1.45145058631897 2016 1.47535490989685 2017 1.46740829944611 2018 1.45610499382019 2019 1.49224412441254 2020 1.60626363754272 2021 1.53002023696899 2022 1.46545016765594