1991

7.0

2013

5.8

1999

8.4

1984

7.2

2003

8.5

1956

7.5

2012

6.2

1978

6.6

2002

5.5

1995

6.9

2009

7.1

1956

7.1

1959

8.1

1990

8.5

2013

6.1

1980

6.7

1993

7.7

2012

6.9

1994

8.7

2007

6.2