Year % 1995 99.51973 2000 97.24541 2006 98.38603 2007 98.21509 2008 99.22479 2009 98.08978 2010 99.18615 2011 99.48943 2012 99.75281 2013 99.80782 2014 99.08036 2015 98.06952 2016 98.17323 2017 98.53003