Year | Value | 2022 | 1.38 | 2021 | 1.389 | 2020 | 1.394 | 2019 | 1.398 | 2018 | 1.412 | 2017 | 1.426 | 2016 | 1.496 | 2015 | 1.576 | 2014 | 1.673 | 2013 | 1.51 | 2012 | 1.744 | 2011 | 1.739 | 2010 | 1.835 | 2009 | 2.009 | 2008 | 1.99 | 2007 | 1.852 | 2006 | 1.786 | 2005 | 2.05 | 2004 | 1.932 | 2003 | 1.921 | 2002 | 1.998 | 2001 | 2.088 | 2000 | 2.097 | 1999 | 2.133 | 1998 | 2.335 | 1997 | 2.399 | 1996 | 2.36 | 1995 | 2.504 | 1994 | 2.482 | 1993 | 2.728 | 1992 | 2.793 | 1991 | 2.604 | 1990 | 2.527 | 1989 | 2.484 | 1988 | 2.478 | 1987 | 2.529 | 1986 | 2.587 | 1985 | 2.63 | 1984 | 2.685 | 1983 | 2.737 | 1982 | 2.802 | 1981 | 2.853 | 1980 | 2.901 | 1979 | 2.983 | 1978 | 3.063 | 1977 | 3.17 | 1976 | 3.221 | 1975 | 3.259 | 1974 | 3.526 |
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