1976

6.0

2007

6.7

1996

7.0

1999

6.8

1993

5.0

2006

6.6

2017

6.0

2017

5.6

1967

6.0

1999

5.5

1997

6.8

1998

7.2

1992

7.4

1969

6.2

2005

6.6

2007

7.4

1980

6.4

1997

7.6

2003

6.1

2007

7.3