1996

6.5

1997

5.4

2007

4.0

1977

6.0

1998

7.3

2001

1.0

2005

5.2

1994

5.6

2011

6.0

1986

5.9

2007

6.0

1994

7.0

1998

0.0

2000

4.1

1971

6.4

2007

2.5

1970

6.2

1999

5.5

2001

5.9

1958

6.7

2009

5.0

1997

0.0

1992

3.4