2002

6.4

1991

7.6

1981

6.2

1969

7.8

2008

6.0

2010

6.3

1979

5.8

1985

8.1

1968

4.2

2008

5.4

1953

7.0

2008

5.5

1997

6.8

1974

6.8

2006

5.6

1997

7.5

2003

5.5

1954

6.7

1993

6.2

2004

5.0