1970

3.7

2016

5.9

2002

6.4

1978

5.4

1997

6.2

1997

5.9

1958

7.7

1971

7.1

2004

6.0

1995

7.8

1974

6.1

2004

6.4

2005

6.2

1983

6.3

1976

5.2

2016

5.0

1984

7.6

1999

3.5

2000

3.4

2009

5.9