Year | Value | 2021 | 2.34 | 2020 | 2.33 | 2019 | 2.22 | 2018 | 2.1 | 2017 | 2.13 | 2016 | 2 | 2015 | 2.14 | 2014 | 2.15 | 2013 | 2.17 | 2012 | 2.13 | 2011 | 2.1 | 2010 | 1.96 | 2009 | 1.73 | 2008 | 1.87 | 2007 | 2.08 | 2006 | 2.03 | 2005 | 2.02 | 2004 | 2.04 | 2003 | 2.08 | 2002 | 2.09 | 2001 | 2.16 | 2000 | 2.16 | 1999 | 2.2000000477 | 1995 | 1.9900000095 | 1992 | 1.7066999674 | 1991 | 1.6612999439 | 1990 | 1.6325999498 | 1980 | 1.5350999832153 | 1975 | 1.111899971962 |
|