1968

7.4

1998

7.1

1998

6.7

2000

6.8

1996

5.5

2005

6.7

1985

8.0

1982

4.8

2017

5.3

1933

0.0

1986

0.0

0.0

2006

7.5

1994

6.8

1955

7.2

1950

8.1

2003

7.8

2001

7.4

2003

7.6

1971

6.4