1982

5.7

1997

6.4

1995

6.4

2006

5.5

2003

5.6

2002

4.5

1992

6.0

2005

4.5

1976

4.1

1972

6.6

1991

8.1

1975

0.0

1989

6.2

2011

4.2

1999

6.8

2010

6.1