1950

8.1

1969

7.1

2015

6.0

2009

8.3

2008

5.5

2004

6.2

2014

6.2

2017

7.2

2017

6.0

1975

8.7

1994

7.5

1929

5.9

1984

8.6

2004

7.3

2006

6.5

1955

7.4

1961

5.6

2009

7.9

2009

8.1

2014

6.8