1997

7.6

1995

8.4

1991

7.6

1931

8.1

1963

7.4

2007

5.8

2007

6.7

2002

7.3

1974

7.1

2018

6.8

2006

2.7

2012

10.0

2000

5.1

2000

5.8

1975

6.8

1994

6.7

1988

7.1

2006

6.5

2008

6.0

2004

4.5