1994

6.5

2004

6.3

1986

6.3

5.2

1995

7.5

2006

5.0

1972

6.2

1976

4.9

1992

7.0

1993

5.7

2014

6.4

2007

7.1

1988

6.3

1998

6.2

2007

5.7

2010

5.4

2000

6.3

1997

6.8

1982

5.4

1998

6.8