1985

7.7

1996

6.4

2006

6.0

1982

6.7

2001

7.4

2004

6.6

1997

7.4

1971

8.2

1942

7.8

1973

7.1

1956

7.7

1999

7.4

1961

7.5

1967

7.5

1990

7.0

1992

8.1

2003

7.2

1989

6.3

1993

6.2

1995

8.0