1993

6.7

2001

6.8

2000

7.1

2006

6.1

2006

5.2

1983

6.4

1973

7.1

1988

6.3

2013

6.7

1965

6.8

1967

6.7

1964

7.0

2005

6.7

1984

5.9

2001

7.1

2018

6.9

2013

6.6

1994

6.0

1997

4.3

1986

6.3