1999

5.4

2002

6.7

1969

7.0

2005

5.7

1987

6.0

2001

6.0

1999

6.4

2005

6.0

2000

6.1

1983

6.5

2005

6.2

2006

6.1

1986

7.0

1999

5.5

1987

6.8

1975

7.2

1981

6.5

1981

6.6

2003

6.1

2003

5.1