| Year | Value | | 2021 | 11.722778283288 | | 2020 | 11.753221872852 | | 2019 | 11.75275726071 | | 2018 | 11.752971692519 | | 2017 | 11.751292186075 | | 2016 | 11.754866180049 | | 2015 | 11.751824817518 | | 2014 | 11.679440389294 | | 2013 | 11.607055961071 | | 2012 | 11.54169202678 | | 2011 | 11.472754946728 | | 2010 | 11.400304414003 | | 2009 | 11.294922468835 | | 2008 | 11.203405290362 | | 2007 | 11.111888111888 | | 2006 | 11.020370933414 | | 2005 | 10.928853754941 | | 2004 | 10.840632603406 | | 2003 | 10.752357773045 | | 2002 | 10.657542579075 | | 2001 | 10.56599756691 | | 2000 | 10.474452554745 | | 1999 | 10.410334346505 | | 1998 | 10.349437860833 | | 1997 | 10.28857837181 | | 1996 | 10.227755845733 | | 1995 | 10.170057698148 | | 1994 | 10.109289617486 | | 1993 | 10.048558421851 | | 1992 | 10.015211439002 |
|