Year % (cumulative) 1975 6.76938009262085 2003 36.6395492553711 2006 26.8970508575439 2008 25.2999992370605 2009 27.0799999237061 2010 27.6000003814697 2011 29.8799991607666 2012 29.4400005340576 2013 29.0300006866455 2014 29.9799995422363 2015 30.1499996185303 2016 30.2099990844727 2017 31.6200008392334 2018 31.8500003814697 2019 33.1399993896484 2021 36.7900009155273 2022 38.1100006103516