Year % (cumulative) 1971 6.59897994995117 2006 30.3827514648438 2007 31.9244918823242 2008 30.6510429382324 2009 31.3353404998779 2010 33.8840599060059 2011 31.8824996948242 2012 37.2988014221191 2013 38.5403785705566 2014 40.1394805908203 2015 40.7780380249023 2016 41.5603141784668 2017 45.1280212402344 2018 43.3992462158203 2019 44.8981399536133 2020 49.1983184814453 2021 50.5028495788574