Year | Value | 2019 | 1,060 | 2018 | 995 | 2017 | 98 | 2016 | 98 | 2014 | 3,444 | 2013 | 3,540 | 2012 | 2,791 | 2011 | 2,815 | 2010 | 2,716.9099276792 | 1991 | 900 | 1990 | 1,600 | 1989 | 1,600 | 1988 | 2,500 | 1987 | 2,800 | 1986 | 2,700 | 1985 | 2,400 | 1984 | 2,600 | 1983 | 2,300 | 1982 | 2,200 | 1981 | 2,600 | 1980 | 3,000 | 1979 | 2,800 | 1978 | 2,800 | 1977 | 2,700 | 1976 | 2,800 | 1975 | 2,800 | 1974 | 2,800 | 1973 | 2,700 | 1972 | 2,600 | 1971 | 2,500 | 1970 | 1,900 |
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