| Year | Value | | 2022 | 0.9929783047703 | | 2021 | 1.0689266670941 | | 2020 | 1.0765522467289 | | 2019 | 1.0749748289067 | | 2018 | 1.1048376797388 | | 2017 | 1.1301459290938 | | 2016 | 1.1633201826835 | | 2015 | 1.1960440040584 | | 2014 | 1.2237834052777 | | 2013 | 1.2499609813316 | | 2012 | 1.275637363676 | | 2011 | 1.3006819921947 | | 2010 | 1.3148378221663 | | 2009 | 1.3052497785878 | | 2008 | 1.2760122139082 | | 2007 | 1.2633758696885 | | 2006 | 1.2944016619021 | | 2005 | 1.3361545606203 | | 2004 | 1.372566714565 | | 2003 | 1.4084492604824 | | 2002 | 1.4436803902991 | | 2001 | 1.4904431556147 | | 2000 | 1.5268788889535 | | 1999 | 1.5485138848381 | | 1998 | 1.6072446361475 | | 1997 | 1.704764411387 | | 1996 | 1.7952931318358 | | 1995 | 1.8702857196121 | | 1994 | 1.9328696210811 | | 1993 | 1.98273369694 | | 1992 | 2.0256453934875 | | 1991 | 2.0739799395386 | | 1990 | 2.1117888667044 | | 1989 | 2.1113201594594 | | 1988 | 2.0920074471526 | | 1987 | 2.0895231405664 | | 1986 | 2.10500688721 | | 1985 | 2.1370111996312 | | 1984 | 2.1706147842773 | | 1983 | 2.1745950225104 | | 1982 | 2.1804656953589 | | 1981 | 2.2240159125319 | | 1980 | 2.2833505774608 | | 1979 | 2.345533294483 | | 1978 | 2.4009034259395 | | 1977 | 2.4482581627715 | | 1976 | 2.4922553425354 | | 1975 | 2.5359922503012 | | 1974 | 2.5922518802783 | | 1973 | 2.6397149075453 | | 1972 | 2.6803705976402 | | 1971 | 2.7320768021239 | | 1970 | 2.7846274569468 | | 1969 | 2.8445394915778 | | 1968 | 2.9250053411623 | | 1967 | 3.0097605254285 | | 1966 | 3.0140006399367 | | 1965 | 3.0549185269125 | | 1964 | 3.1543830622972 | | 1963 | 3.2037002451404 | | 1962 | 3.2544242911112 | | 1961 | 3.2924782241307 |
|