1978

6.9

1991

5.6

1993

5.5

2018

6.9

1987

6.0

1981

6.0

1984

7.5

1977

5.0

1996

8.9

1992

1.7

1994

7.1

1984

6.3

2005

8.3

1975

5.1

1995

7.7