Year | Value | 2021 | 10.266917244078 | 2017 | 12.493095478006 | 2016 | 11.884378155613 | 2015 | 11.845524928581 | 2014 | 11.581799088011 | 2013 | 11.516275911085 | 2012 | 11.799981725247 | 2011 | 11.702094716865 | 2010 | 11.013495555369 | 2009 | 10.453599138637 | 2008 | 10.332680701625 | 2007 | 10.432170130726 | 2006 | 11.175138391165 | 2005 | 12.267507853566 | 2004 | 11.83215591667 | 2002 | 13.597677371279 | 1991 | 12.413358271978 |
|