1979

6.0

1982

6.7

2007

7.2

2020

6.5

2013

5.3

2007

6.0

2009

5.3

2017

6.8

1969

7.6

1999

5.9

1964

7.0

2008

5.8

1986

7.7

2013

7.6

2006

6.8

1965

6.8

1967

7.3

1995

4.6

1987

6.7

1993

6.6