2007

5.7

2006

7.6

1999

7.0

1987

6.9

2002

6.8

1967

7.3

1990

6.4

1999

5.8

2006

5.9

1993

7.2

1996

6.1

2005

6.7

2006

7.7

1955

7.3

1956

7.1

2004

6.2

1970

7.1

2000

7.1

1989

7.4

2002

7.0