1979

8.3

2002

7.2

1997

7.1

1987

8.1

2013

7.8

1971

0.0

2017

5.5

1960

7.2

1996

6.5

2002

7.1

1998

6.4

2005

5.2

1996

7.1

1998

5.4

1986

5.6

2007

7.0

1995

7.2

2003

6.9

1988

6.8

1986

6.9