1968

8.1

1998

6.8

2000

8.2

1979

6.5

2009

7.4

1993

7.2

1985

6.2

1999

4.8

2004

5.2

2004

6.2

2020

5.7

2025

8.0

1957

5.8

1997

6.5

1992

6.4

2005

6.7

1999

7.0

2012

5.7

2008

8.1

1996

5.4