1997

5.7

2008

5.0

2006

6.5

9.5

2002

6.2

2001

6.8

1978

6.3

1988

6.2

1974

6.8

1979

0.0

1973

6.6

2003

5.0

2001

6.7

1995

5.2

1999

6.1

1958

7.5

1989

6.1

1962

5.7

2004

6.3

2006

5.5