1977

4.1

1997

7.6

2003

6.1

1982

6.6

1967

7.5

1992

8.1

1995

8.0

1988

7.2

1995

8.2

1996

6.6

1988

7.8

2001

7.4

2004

6.6

1997

7.4

1956

7.7

2007

6.7

1960

6.4

2006

7.4

2024

6.7

2016

6.5