2003

8.0

2002

7.5

2000

7.4

2003

7.2

1981

7.1

2007

6.1

2006

6.9

1991

6.2

1990

6.7

1993

5.5

1982

4.7

1978

4.3

1999

5.0

1999

8.2

2003

7.1

2003

6.7

1974

6.4

0.0

0.0

1992

4.0