1970

5.6

1991

9.3

2002

7.1

1995

6.5

1992

6.6

2002

7.0

1999

6.5

1988

7.1

1990

6.7

1990

6.0

2002

6.2

1988

6.8

2002

6.6

1997

6.2

1996

4.9

1997

6.3

2003

7.1

1994

6.7

1995

6.9

2003

6.3