2008

8.7

2009

5.3

2015

6.4

1997

6.0

1999

6.9

2013

5.5

1994

7.4

1998

6.0

1994

6.0

1971

6.4

1994

8.1

1990

6.5

1967

7.3

1960

7.7

2005

5.2

2011

7.5

2004

5.7

2011

6.3

2001

6.2

1987

5.3