1980

6.6

2002

7.4

1981

6.8

1982

6.8

1984

6.1

1972

3.2

2008

5.5

2002

3.7

1986

5.2

1966

6.1

1994

5.3

2000

4.8

1981

7.0

2005

3.3

1995

5.7

1923

6.8

1940

6.0

2003

7.1

2013

6.9

1993

6.4