1957

8.3

1959

7.2

1998

6.3

1968

6.3

1986

6.7

2006

4.1

2018

7.8

2021

6.2

1981

8.1

2004

7.9

1993

8.6

1983

7.5

2008

7.8

1997

5.5

2021

6.1

1965

6.9

1969

7.9

2008

6.6

2001

7.3

2007

7.0