1951 154
1952 49.6
1953 46.7
1954 58.3
1955 70.5
1956 90
1957 70.1
1958 105.7
1959 37.4
1960 40.8
1961 34.7
1962 58.9
1963 72.2
1964 30
1965 71.6
1966 100
1967 33.7
1968 49.9
1969 56.1
1970 142.3
1971 28.6
1972 54.8
1973 74.1
1974 60
1975 50.9
1976 38.6
1977 53.4
1978 132.5
1979 50.7
1980 40.8
1981 84.3
1982 38.8
1983 27.4
1984 67
1985 118.7
1986 23.2
1987 55
1988 67.9
1989 87.3
1990 89
1991 98.7
1992 47.1
1993 71.6
1994 83.6
1995 44.3
1996 41.2
1997 35.9
1998 44.3
1999 410.4