1989

8.4

1999

7.5

1997

7.4

1962

7.3

2013

8.5

2016

9.3

1995

7.2

1998

7.0

1960

7.1

2001

8.1

1983

6.8

2000

6.2

1995

7.6

1999

6.9

1999

7.9

2010

7.9

2015

8.0

2001

7.6

1960

7.4

2020

7.8