Year Number 1996 83.5 1998 86.5671615600586 2000 80.5970153808594 2002 83.5820922851563 2003 81.0945281982422 2004 80.288459777832 2005 81.25 2006 86.0576934814453 2007 81.7307662963867 2008 79.8076934814453 2009 82.4644546508789 2010 78.1990509033203 2011 75.1173706054688 2012 77.9342727661133 2013 77.4647903442383 2014 81.7733993530273 2015 83.2512283325195 2016 82.7586212158203 2017 81.7733993530273 2018 80.5825271606445 2019 81.6425094604492 2020 80.6763305664063 2021 81.6425094604492 2022 85.0241546630859