1986

5.1

1982

5.7

1997

6.4

1995

6.2

2006

5.5

2003

5.3

2002

4.5

1992

6.0

2005

4.5

1976

4.1

1972

6.5

1991

8.1

1975

0.0

1989

6.1

2011

5.4

1999

6.4

2010

6.1