1997

6.6

1967

7.6

2006

6.8

1989

7.5

1999

7.0

2005

6.8

2002

3.7

1981

7.1

1987

7.8

1990

6.0

2004

0.0

1991

6.5

2016

6.9

1975

3.5

2006

6.6

1936

5.9

1960

4.2

1968

5.8

2001

6.2

1986

7.0