1970

6.1

2003

6.0

2000

5.5

2011

7.4

1994

7.7

2021

6.8

2011

7.5

2014

6.5

2002

8.4

1977

6.7

1985

6.4

2002

7.8

1985

5.4

2011

6.3

2001

6.5

2011

6.8

1941

7.3

1995

5.7

1964

5.7

2014

5.0