1977

6.8

1983

6.2

1971

7.1

1999

6.5

2003

6.4

2002

7.1

1997

6.5

1996

7.1

2017

6.2

1993

6.7

1987

6.5

2006

7.4

1970

7.1

1965

7.1

1988

2.0

1998

2.0

1994

5.7

1983

6.2

2007

7.9

1973

3.1