1995

7.2

2004

6.0

1999

6.0

1997

5.7

2002

6.2

2001

6.8

1978

6.3

1988

6.2

2002

6.6

2004

3.7

1928

0.0

1998

4.4

2006

6.5

1998

6.8

1998

7.1

1965

5.9

1993

6.0

1975

7.3

2005

6.9

1982

5.2