| Year | Value | | 2021 | 1.2613032172934 | | 2020 | 1.2613032172934 | | 2019 | 1.2613032172934 | | 2018 | 1.2613032172934 | | 2017 | 1.2613032172934 | | 2016 | 1.2613032172934 | | 2015 | 1.2613032172934 | | 2014 | 1.2613032172934 | | 2013 | 1.2613032172934 | | 2012 | 1.2613032172934 | | 2011 | 1.2613032172934 | | 2010 | 1.2613032172934 | | 2009 | 1.2613032172934 | | 2008 | 1.2613032172934 | | 2007 | 1.2613032172934 | | 2006 | 1.2613032172934 | | 2005 | 1.2613032172934 | | 2004 | 1.2613032172934 | | 2003 | 1.2613032172934 | | 2002 | 1.2613032172934 | | 2001 | 1.2613032172934 | | 2000 | 1.2613032172934 | | 1999 | 1.2613032172934 | | 1998 | 1.2613032172934 | | 1997 | 1.2613032172934 | | 1996 | 1.2613032172934 | | 1995 | 1.2613032172934 | | 1994 | 1.2380176194357 | | 1993 | 1.2302557534831 | | 1992 | 1.2224938875306 | | 1991 | 1.214732021578 | | 1990 | 1.2069701556254 | | 1989 | 1.1992082896728 | | 1988 | 1.1914464237203 | | 1987 | 1.1836845577677 | | 1986 | 1.1759226918151 | | 1985 | 1.1681608258625 | | 1984 | 1.16039895991 | | 1983 | 1.1526370939574 | | 1982 | 1.1448752280048 | | 1981 | 1.1371133620522 | | 1980 | 1.1293514960997 | | 1979 | 1.1215896301471 | | 1978 | 1.1138277641945 | | 1977 | 1.0594947025265 | | 1976 | 1.0012807078822 | | 1975 | 0.9003764504987 | | 1974 | 0.85380525478325 | | 1973 | 0.81499592502037 | | 1972 | 0.7761865952575 | | 1971 | 0.73737726549463 | | 1970 | 0.69856793573175 | | 1969 | 0.65975860596888 | | 1968 | 0.620949276206 | | 1967 | 0.58213994644312 | | 1966 | 0.54333061668025 | | 1965 | 0.50452128691737 | | 1964 | 0.4657119571545 | | 1963 | 0.42690262739162 | | 1962 | 0.38809329762875 | | 1961 | 0.34928396786588 |
|