1985

6.9

1993

6.3

1979

5.9

2020

7.0

2003

5.8

1970

7.5

1993

6.0

1978

7.1

1978

7.2

2005

6.9

2003

4.2

2005

7.0

1997

7.8

1974

8.1

2006

6.7

1995

7.1

1995

7.2

1996

6.8

2005

8.6

2005

7.7