2003

7.5

1991

7.5

2006

8.0

2001

5.4

1998

6.8

1968

5.8

2007

2.0

1993

7.6

1988

1.0

1992

4.3

1977

8.5

1999

6.7

2004

5.9

2006

5.5

2008

5.5

1999

5.1

2007

5.4

2005

5.7

1965

7.2

2010

6.3