1999

6.8

1955

7.3

1988

5.0

1998

7.7

2006

6.0

2007

5.9

1993

7.7

1990

5.7

2006

6.9

1987

7.2

2010

7.0

1997

5.1

2007

5.4

2003

5.8

2005

6.2

2003

6.2

1992

7.0

1960

8.0

1944

7.2

1992

6.6