1954

6.8

1998

6.9

2008

6.3

1953

7.2

2013

1.0

1984

4.3

1981

7.0

1969

5.3

1980

7.8

2005

5.6

1993

7.2

1939

7.1

2002

7.1

1986

8.0

1979

7.3

1993

6.9

1998

4.2

1975

6.6

2006

4.3

2006

2.9