2006

5.8

2007

6.4

2002

5.3

2006

4.9

2002

6.8

1997

6.6

1998

7.5

2004

6.0

2004

5.8

1977

7.1

1978

3.5

1993

7.5

1994

6.5

1999

6.1

1995

6.0

1996

6.1

2017

5.5

1997

6.2

2002

6.2

1983

6.4