1980

8.6

2002

5.2

2007

7.9

2004

6.6

2011

7.0

2010

7.8

2015

7.0

0.0

1973

5.0

1978

7.7

1980

7.0

1987

8.4

1966

8.0

2001

7.6

1999

7.5

1999

8.4

1988

8.0

1995

7.8

1999

6.8

2004

8.2