1975

7.0

2003

7.4

1969

5.0

1984

7.9

1985

7.4

1967

7.3

1997

8.1

1981

6.1

2002

5.1

1977

5.8

2007

6.2

1998

8.2

2012

0.0

2015

7.5

2014

6.9

2015

7.2

2015

7.3

2015

6.7

1984

6.9

2014

7.7