Year % 1990 56.5356548457304 1991 57.2706935123042 1992 57.8523378456939 1993 58.2551870609378 1994 58.673647469459 1995 59.036455643912 1996 59.28589716733 1997 59.4673476833272 1998 59.6246022475531 1999 59.7553246653479 2000 59.8694002083643 2001 59.96541996542 2002 60.0380282700725 2003 60.1040052715001 2004 60.1541089796064 2005 60.2837256256309 2006 60.3028838408249 2007 60.306336247381 2008 60.5281878001067 2009 60.8387630571931 2010 61.1792500251332 2011 61.5077743079967 2012 61.8360424932804 2013 62.2756470810504 2014 62.7392446787008 2015 63.1474257166207 2016 63.5164936138932 2017 63.9011299004285 2018 64.3714495143852 2019 64.8484104954837 2020 65.193183216439 2021 65.4939253129969 2022 65.7312793117371