1972

7.1

2014

8.4

2018

8.2

2017

7.0

1999

8.4

2016

7.3

2001

7.9

2011

7.6

2012

6.6

1991

8.3

1980

8.2

1990

8.5

2016

7.4

2012

7.3

2018

7.4

2014

8.0

1987

6.5

2015

7.3

1969

7.1

1993

8.0