1985

7.0

1993

7.5

1971

7.6

2004

7.5

1987

6.1

2017

6.0

2005

6.5

2000

7.1

1997

7.9

2001

6.9

1979

7.7

1977

7.7

2000

7.0

2001

6.8

1994

6.7

1999

6.6

1997

6.8

1988

7.2

1983

6.8

2013

3.8