1953

6.4

2006

5.8

2004

7.7

2006

7.5

1974

8.6

1990

7.2

1970

7.1

2003

7.2

1984

8.0

1990

7.5

2016

6.5

2000

8.1

2001

7.4

2005

6.7

1966

8.2

1991

7.6

2001

7.5

2001

7.1

2005

5.5

1961

5.7