Year % (cumulative) 1989 14.2857704162598 2000 24.5219402313232 2006 27.2798500061035 2007 26.0960292816162 2008 26.3541698455811 2009 26.0251293182373 2010 25.9060001373291 2011 27.6761302947998 2012 28.482400894165 2013 28.9320602416992 2014 28.2993392944336 2015 28.1919803619385 2016 29.3149108886719 2017 30.0049304962158 2018 30.8275508880615 2019 30.7363147735596 2020 32.9999618530273 2021 30.0783462524414 2022 31.0636806488037