1999

8.0

2017

7.7

2013

6.6

2016

7.0

1973

8.0

1958

7.1

2013

7.3

1969

6.0

1986

7.6

2010

6.1

2013

6.0

1955

7.9

1978

6.8

2013

7.4

2009

6.6

1962

7.9

1992

6.3

1974

7.9

2000

5.7

2014

6.5