1991

7.5

2007

6.1

2006

5.8

2006

7.0

1980

7.8

2002

5.9

2008

5.5

1970

6.1

2001

7.0

1976

7.2

2020

6.6

1978

6.5

1937

6.8

2022

5.6

1922

0.0

2006

6.9

2000

7.1

2007

7.4

2018

7.7

1968

6.3