|
| 1961 | 5,28 |
| 1962 | 5,28 |
| 1963 | 5,28 |
| 1964 | 5,28 |
| 1965 | 5,28 |
| 1966 | 5,28 |
| 1967 | 5,35 |
| 1968 | 5,35 |
| 1969 | 5,35 |
| 1970 | 5,35 |
| 1971 | 5,35 |
| 1972 | 5,38 |
| 1973 | 5,47 |
| 1974 | 5,58 |
| 1975 | 5,71 |
| 1976 | 5,79 |
| 1977 | 5,91 |
| 1978 | 6,01 |
| 1979 | 6,05 |
| 1980 | 6,15 |
| 1981 | 6,19 |
| 1982 | 6,26 |
| 1983 | 6,40 |
| 1984 | 7,24 |
| 1985 | 7,48 |
| 1986 | 7,48 |
| 1987 | 7,55 |
| 1988 | 7,61 |
| 1989 | 7,61 |
| 1990 | 7,64 |
| 1991 | 7,70 |
| 1992 | 8,18 |
| 1993 | 9,13 |
| 1994 | 9,43 |
| 1995 | 9,43 |
| 1996 | 9,43 |
| 1997 | 9,12 |
| 1998 | 9,12 |
| 1999 | 8,81 |
| 2000 | 8,81 |
| 2001 | 8,81 |
| 2002 | 8,81 |
| 2003 | 8,81 |
| 2004 | 8,81 |
| 2005 | 8,81 |
| 2006 | 8,81 |
| 2007 | 9,12 |
| 2008 | 9,12 |
| 2009 | 9,12 |
| 2010 | 9,12 |
| 2011 | 9,12 |
| 2012 | 9,12 |
| 2013 | 9,12 |
| 2014* | 9,12 |
| 2015* | 9,12 |
| 2016* | 9,12 |
| 2017* | 9,12 |
|
