1980

7.7

1959

8.1

2001

6.9

1987

7.2

1998

7.2

1995

8.0

1999

7.6

1994

6.6

2007

7.3

1992

6.7

1993

6.1

2004

6.5

1995

6.8

1992

6.6

2010

7.8

2003

6.4

1978

6.7

0.0

1998

5.3

2009

6.1