1990

5.9

2010

8.2

2020

7.2

1997

7.9

1988

6.2

1998

8.1

1985

8.3

1968

8.1

1987

7.3

1992

7.4

1972

8.7

1959

8.1

1995

5.8

1954

6.7

2006

7.2

2010

6.5

2023

8.0

2003

5.5

1980

7.3

1985

7.7