2012

6.4

2010

5.6

1997

6.4

1990

7.5

1995

6.9

1995

7.3

2011

7.2

2012

6.0

1973

8.0

2002

6.5

1979

7.3

2000

5.8

1991

6.8

1998

7.5

2006

7.5

2003

6.5

1993

5.5

1989

7.0

1983

6.3

1986

7.4