1977

7.4

2011

8.5

2015

7.5

2014

7.6

2012

7.5

2015

7.8

1994

8.4

2010

8.1

2010

8.1

2014

7.8

1994

7.8

2012

7.6

1969

8.3

1990

8.3

1995

7.3

2021

8.8

1963

7.9

2016

7.3

2016

7.1

2012

8.2