Year | Value | 2021 | 20.150541691574 | 2020 | 20.290282158528 | 2019 | 20.428171972898 | 2018 | 20.56882725768 | 2017 | 20.704560710112 | 2016 | 20.843053633875 | 2015 | 20.987109081923 | 2014 | 21.12391301608 | 2013 | 21.260573009891 | 2012 | 21.397245257579 | 2011 | 21.716492422122 | 2010 | 21.854801076878 | 2009 | 21.966029050639 | 2008 | 22.076292799429 | 2007 | 22.186450555363 | 2006 | 22.296751381902 | 2005 | 22.407046541521 | 2004 | 22.517331722539 | 2003 | 22.859831036329 | 2002 | 22.970876827848 | 2001 | 23.08222274277 | 2000 | 23.193568657692 | 1999 | 23.309152857184 | 1998 | 23.424737056677 | 1997 | 23.540321256169 | 1996 | 23.655905455661 | 1995 | 23.771489655153 | 1994 | 23.887073854646 | 1993 | 24.002658054138 | 1992 | 24.11824225363 | 1991 | 24.233826453122 | 1990 | 24.349410652615 |
|