2003

7.1

1982

7.8

1998

7.3

2006

6.1

2005

7.1

2007

6.7

2002

5.9

2007

6.7

2007

6.4

1992

6.7

1993

6.1

1999

5.7

1987

6.7

2001

6.0

1994

7.3

1998

4.0

1994

6.0

1977

6.2

1993

6.4

2009

4.2