1999

7.4

2003

5.8

1988

5.0

1977

3.8

1996

6.6

2002

7.1

2001

6.7

1999

6.8

1998

6.6

1993

5.5

1997

6.1

1997

4.5

2006

5.4

2004

4.8

2001

6.1

2005

5.5

2004

5.5

2000

5.1

2004

4.8

1969

5.1