Year % 1987 21.2270163288027 1988 43.22756102276112 1989 41.514823121940005 1990 63.180434566457414 1991 57.15914377106615 1992 58.9678929574966 1993 62.41998639056017 1994 62.75226226969371 1995 65.76095498553785 1996 62.87759611557124 1997 64.61320272816576 1998 64.66579992094812 1999 67.15017126652674 2000 70.49593020950151 2001 72.91593635946559 2002 74.70733375082466 2003 74.98565257409163 2004 76.99570832251473 2005 74.74118198808192 2006 75.43089439776739 2007 75.3976638986358 2008 76.57698529268359 2009 78.19730752778263 2010 81.80415675587332 2011 82.38347754324153 2012 82.42966308252454 2013 81.14880283200985 2014 81.09618379661036 2015 81.58984364847831 2016 80.21830207602419 2017 82.93470824283807 2018 82.83042859281753 2019 82.89356275950603 2020 82.25192630111034 2021 82.96080803391668 2022 82.71722983364732