1991

8.0

2003

7.8

2001

7.2

2000

8.0

1991

5.3

1990

6.9

1998

6.1

1993

7.7

1995

7.0

1981

3.0

1989

6.4

1992

6.7

1991

6.0

2005

7.5

1992

5.9

1957

6.3

1996

5.0

1982

6.1

1980

4.6

1993

7.9

1995

7.8

2001

4.2

1999

0.0

1997

8.0

1973

0.0

1976

6.9

1991

5.0

1997

10.0

1988

6.2

1998

6.8