2009

9.5

2011

6.1

2007

7.5

1975

6.8

2004

5.9

1982

6.8

1985

7.2

2013

6.3

1990

6.6

2000

5.5

2009

5.6

1993

7.6

1999

6.7

1996

6.1

1993

7.0

1956

7.1

1986

6.8

1967

7.3

1956

7.8

1989

7.2