1996

6.4

1986

4.0

2004

7.9

2000

7.6

1984

1.0

2005

8.2

2007

6.5

1985

7.7

2007

8.1

1969

6.1

1981

5.7

1994

8.5

2001

8.0

1978

4.3

1987

8.4

2001

6.8

2001

5.5

1975

7.0