Year % 2005 3.52553179140661 2006 3.46066404520994 2007 2.98260391267765 2008 3.10639256827815 2009 4.21499469701351 2010 3.10772417173934 2011 3.46686409051456 2012 3.44682339262827 2013 2.85728229301093 2014 2.25174733022776 2015 2.84649627717535 2016 3.08157613195282 2017 2.8789163660392 2018 2.59786426236426 2019 2.65554756569737 2020 1.86754766697946 2021 2.07937608671228 2022 2.64123318576759