1999

7.2

1970

7.5

2004

7.1

2007

7.2

2007

6.4

1958

7.7

1993

7.2

1980

6.7

2005

6.3

1984

8.0

1996

6.0

1989

6.3

1974

7.2

1992

5.3

1993

8.0

1995

6.8

1988

7.8

1989

7.0

1981

7.4

2009

5.5