| Year | Value | | 1998 | 0.8000000119 | | 1997 | 0.8999999762 | | 1996 | 0.8999999762 | | 1995 | 0.8999999762 | | 1994 | 0.8000000119 | | 1993 | 0.8000000119 | | 1992 | 0.8000000119 | | 1991 | 0.8000000119 | | 1990 | 0.8000000119 | | 1989 | 1 | | 1987 | 0.1000000015 | | 1986 | 0.1000000015 | | 1985 | 0.1000000015 | | 1984 | 1.7000000477 | | 1983 | 1.5 | | 1982 | 0.3000000119 | | 1981 | 0.3000000119 |
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