1972

8.7

1974

8.6

1990

7.4

1995

8.0

1995

6.5

1983

8.2

1990

8.5

1954

7.9

1977

5.0

1984

8.4

2003

6.1

2000

5.8

2006

8.2

2014

5.9

2016

5.5

1993

6.3

1984

6.5

1990

6.9

1993

7.9

2016

5.8