Year % 1990 53.33183222207134 1991 53.55023087760841 1992 53.785995752927 1993 54.35748926018894 1994 54.52911429373579 1995 54.866225614552235 1996 54.88358331872512 1997 54.9288738071573 1998 54.983709941168364 1999 55.05198185351895 2000 55.17673286686346 2001 55.23370689511973 2002 55.318393174442335 2003 55.34334341247997 2004 55.4040726476106 2005 55.50561856409065 2006 55.57441758617733 2007 55.65917528884632 2008 55.76717861024247 2009 55.88590579919285 2010 56.026168084336355 2011 56.23059771372141 2012 56.51360761203027 2013 56.77762281565043 2014 57.16553333622025 2015 57.516906737176946 2016 57.807315370961554 2017 58.12495656248334 2018 58.43629219869706 2019 58.741135539598915 2020 59.027004530479765 2021 59.21329587050454 2022 59.47328384316611