| Year | Value | | 2022 | 1.00120092261 | | 2021 | 1.0709196017196 | | 2020 | 1.1083345135981 | | 2019 | 1.1125711544107 | | 2018 | 1.2073854252962 | | 2017 | 1.2375939335197 | | 2016 | 1.2473098007716 | | 2015 | 1.2031694077685 | | 2014 | 1.1994333671281 | | 2013 | 1.3953965080368 | | 2012 | 1.4895772900813 | | 2011 | 1.3797430458596 | | 2010 | 1.3699852575929 | | 2009 | 1.3650757168135 | | 2008 | 1.6158502942742 | | 2007 | 1.5479122799817 | | 2006 | 1.4551774101644 | | 2005 | 1.6905870137942 | | 2004 | 1.6141942369264 | | 2003 | 1.6500998427256 | | 2002 | 1.6324078112129 | | 2001 | 1.5047549019608 | | 2000 | 1.313742032246 | | 1999 | 1.1869741480546 | | 1998 | 1.2201225188292 | | 1997 | 1.3406385983861 | | 1996 | 1.4179547033567 | | 1995 | 1.6467162313649 | | 1994 | 1.6412528075867 | | 1993 | 1.8377415951273 | | 1992 | 1.9007467624539 | | 1991 | 2.3542580898355 | | 1990 | 2.8882149578594 | | 1989 | 2.7408516862969 | | 1988 | 2.945553394976 | | 1987 | 3.1337434912212 | | 1986 | 2.5035753200763 | | 1985 | 2.3757574555444 | | 1984 | 3.4769124741558 | | 1983 | 4.1952339243106 | | 1982 | 4.5727831793039 | | 1981 | 4.2253248387909 | | 1980 | 4.515319835155 | | 1979 | 5.5016058467997 | | 1978 | 5.1992921547148 | | 1977 | 3.7401755405364 | | 1976 | 2.4847429778578 | | 1975 | 1.8789025543992 | | 1974 | 1.7770025564551 | | 1973 | 1.6592780240659 | | 1972 | 1.5418118466899 | | 1971 | 1.2277150642273 | | 1970 | 1.0574832594139 | | 1969 | 1.080069124424 | | 1968 | 1.2183428869203 | | 1967 | 1.304993715004 | | 1966 | 1.1332684824903 | | 1965 | 0.99033478078162 | | 1964 | 0.58988764044944 | | 1963 | 0.20648967551622 |
|