2008

6.8

2002

7.1

2008

6.1

2000

6.4

1990

6.1

2008

7.4

1980

5.6

1988

7.5

2002

3.7

1993

6.2

1990

6.7

1996

5.5

2002

6.2

1993

6.5

1991

6.2

1992

6.3

1984

6.1

2003

5.7

1994

5.2

1995

5.9