Year % (cumulative) 1971 54.0457992553711 1981 66.1198577880859 1991 66.6810913085938 2005 82.1544799804688 2007 83.0205993652344 2008 83.5525894165039 2009 84.1971817016602 2010 84.4569396972656 2011 84.3671875 2012 84.6652374267578 2013 84.5956497192383 2014 85.7652587890625 2015 86.0193405151367 2016 86.0288391113281 2017 85.9386367797852 2018 86.3136596679688 2019 86.2792816162109 2020 86.4138565063477 2021 86.6609191894531