2002

6.6

2000

6.3

1976

7.5

1988

5.5

1978

7.5

1993

6.5

1968

6.4

1991

6.2

2010

8.2

2004

7.8

2011

5.1

1974

7.4

2002

6.3

1974

6.4

1997

7.1

2008

7.6

2013

6.0

2002

6.7

1980

6.9

1958

8.2