1989

8.2

1986

6.1

1997

6.0

1978

7.8

1999

0.0

2000

8.0

1997

7.5

1993

6.1

2003

7.4

1984

5.3

1984

8.1

1999

4.0

1999

0.0

2010

2.0

1992

7.2

1988

5.0

1977

7.4

1996

7.8