1979

7.0

2012

7.4

2016

7.3

1977

7.7

1989

8.3

1984

7.7

1957

8.2

1997

8.4

2018

6.9

2015

7.5

2007

6.4

1994

8.7

2012

7.7

2009

7.8

2016

7.9

1976

8.1

2018

8.0

1997

6.8

1961

7.6

2014

7.4