1999

7.0

1973

7.4

1972

7.4

1998

6.3

1995

6.3

1993

7.5

1985

7.5

2003

6.7

2008

5.9

2007

7.9

2011

6.0

1985

6.8

1975

6.2

2002

7.8

1989

7.6

2002

6.8

2001

4.9

2000

5.7

1949

0.0

1986

7.4