1967      .    .   191.1    .
 1968      .  9.5   797.9    .
 1969      . 19.9   207.3    .
 1970      . 16.7   521.2    .
 1971      . 13.5  2585.1    .
 1972  3.410 19.3  2707.6 0.30
 1973  4.044 19.6  1967.1 0.22
 1974  6.350 12.7  2353.5 0.19
 1975  4.935 14.9   646.0 0.20
 1976  6.111 11.2  2585.4 0.20
 1977  7.040  4.2  2533.3 0.20
 1978  7.146  7.2  2556.9 0.12
 1979  7.416  4.4 12296.1 0.52
 1980 14.892  5.4  6419.0 0.30
 1981 13.734 10.7  7137.4 0.30
 1982 14.280 13.5  8489.0 0.42
 1983 13.114  4.9  8906.0 0.18
 1984 12.076  4.5  6275.2 0.13
 1985 12.771 15.9  4842.5 0.20
 1986 14.194 17.5  4882.6 0.09
 1987 12.876 15.6  5078.3 0.10
 1988 11.959 11.6  5236.9 0.07
 1989 10.438    .  4915.7 0.03
 1990  7.497    .  2820.4 0.05
 1991  5.868    .  3559.0 0.18
 1992  4.277    .  3789.0 0.20