Year % 1990 54.09328981071555 1991 54.320953895574 1992 54.872318717496654 1993 55.74813165824167 1994 55.7793055879319 1995 56.10638946923886 1996 56.29242650966844 1997 56.35494932085944 1998 56.39493507904302 1999 56.46445682305951 2000 56.48546263112771 2001 56.89169610396436 2002 56.92218440383324 2003 56.97027412247475 2004 57.03216666584155 2005 57.139769513625126 2006 57.153269915910315 2007 57.222095216076376 2008 57.31473562459314 2009 57.38088858450079 2010 57.45491522140187 2011 57.58217175569126 2012 57.81729984024837 2013 58.13318018292731 2014 58.52949216262255 2015 58.85466885767817 2016 59.174162246587805 2017 59.47800581306787 2018 59.7649453503928 2019 60.09693439695192 2020 60.363891528291354 2021 60.60385991841693 2022 60.86085233042676