1993

8.2

1974

8.0

1997

5.6

2005

6.8

1978

7.7

1990

7.8

2006

5.0

1990

7.9

2005

6.7

1999

7.0

2001

6.4

1964

8.0

2004

6.6

2001

6.5

1991

7.8

2002

6.5

1997

7.3

1969

6.7

1998

7.1

1978

7.1