1994

8.3

2005

6.6

2008

6.7

2007

6.5

1987

6.6

1999

6.5

2008

7.3

2004

6.2

1991

6.1

1983

7.4

1990

6.0

1993

7.3

1978

6.3

2006

5.5

1991

6.2

1996

6.6

1989

6.5

1996

5.5

2005

6.5

1984

6.8