2005

6.5

2004

6.0

1999

6.6

1992

6.6

1990

6.7

1988

6.1

2001

7.0

1993

8.1

1995

6.8

1976

6.7

2005

6.5

2016

3.0

1994

5.0

2007

6.1

2008

7.1

2008

6.2

2006

5.7

1994

7.2

1998

6.3

2007

6.2