1993

4.7

2004

4.4

2006

3.2

1977

5.7

2005

8.9

2005

6.8

2002

7.0

2005

7.3

1992

8.0

1993

4.5

1977

8.1

1976

7.8

1977

7.9

1997

3.5

1976

8.1