Year % 2000 3.23197912976149 2001 3.19232564290581 2002 3.17197077379858 2003 2.77186220836284 2004 2.6671914849082 2005 2.5457408786114 2006 2.48161399813269 2007 2.45178874632406 2008 2.30508690672553 2009 2.26952704259959 2010 2.20587725182095 2011 2.10717876157705 2012 1.88415612436829 2013 1.90374440536556 2014 1.84454697329217 2015 1.6416386800496 2016 1.63547434615255 2017 1.4875798146223 2018 1.45661045489384 2019 1.49111251965762 2020 1.30504082647375