1994

5.5

2004

5.6

1999

6.1

2002

6.1

2004

4.7

1980

6.2

1996

6.2

1999

6.2

1984

6.0

1994

7.1

2007

6.0

1987

6.3

1955

7.0

1983

6.7

2005

6.7

2013

6.5

1987

6.8

2001

5.8

2018

6.2

2013

6.3