1962     .     .   235      .
 1963     .     .   611      .
 1964     .     .   746      .
 1965     .     .   695      .
 1966     .     . 10006      .
 1967     .  1.52  2714      .
 1968  41.4  0.66  4562      .
 1969  27.4  3.19  9303      .
 1970  36.7  2.76  5765      .
 1971 103.8  1.55 11643      .
 1972 126.6  2.58 24063      .
 1973 178.7  2.66 18902      .
 1974 221.9  3.97 24676      .
 1975 105.1  1.20 22671      .
 1976  96.3  0.53 17341      .
 1977  77.3  1.24  8131      .
 1978  87.4  1.82  1534      .
 1979  52.3  0.84  6271      .
 1980 168.1  5.06  5354      .
 1981 293.8  1.17 10192      .
 1982 488.6  7.03  7147 0.0738
 1983 107.8  0.35  5968 0.0487
 1984 143.1  9.10  5361  0.067
 1985 442.6  1.96  6107 0.0327
 1986 194.8  7.22  4506 0.0606
 1987 309.6  1.98  4484 0.0327
 1988 459.4  2.68  4987 0.0231
 1989 202.6  1.71  6676 0.0961
 1990 471.0  2.41 17788 0.0808
 1991 250.3  1.73 15183 0.1043
 1992 322.4  1.21 18987 0.1651
 1993 262.5  9.82 23305  0.113
 1994 142.4  0.59 21742 0.2377
 1995 131.9  2.12 24359 0.3201
 1996 229.9  0.10 28058 0.1777
 1997 101.2     .     . 0.4054