1954

6.1

1986

6.0

1994

7.2

1985

6.8

1981

5.5

1988

6.9

1981

7.6

1985

5.0

1993

8.1

1984

7.1

1992

4.4

1984

6.8

1999

7.3

1990

6.6

1968

5.5

1993

6.9

1985

7.8

1992

5.7

1984

7.5

1951

6.0

1969

6.9

1962

6.9

1987

4.8

1971

6.6

1955

6.3

1975

6.7

1951

6.8