Year % (cumulative) 1981 12.6999998092651 2001 33.8268394470215 2005 38.6766014099121 2006 39.6553916931152 2007 41.6584815979004 2008 42.7378005981445 2009 43.2603988647461 2010 44.104419708252 2011 45.0158805847168 2012 46.297908782959 2013 47.1846618652344 2014 47.5720481872559 2015 48.2238311767578 2016 49.4914169311523 2017 50.3840065002441 2018 51.3599586486816 2019 52.2374305725098 2020 51.7724113464355 2021 52.2724952697754 2022 52.8150787353516