2004

6.6

2006

6.5

2002

6.2

1983

4.5

1981

6.3

1988

6.3

2007

6.6

2008

7.0

1997

6.0

2018

6.7

1980

6.6

1982

6.4

2001

7.9

2003

6.6

1968

7.3

1962

7.2

1970

7.1

1979

7.0

2005

6.6

2006

6.7