1991

6.2

2016

6.3

2013

6.3

1979

7.3

1998

6.5

2016

6.6

1994

6.2

1994

6.6

2016

7.4

2006

7.0

2013

6.6

2010

5.2

2009

6.8

1982

5.2

1977

6.7

2004

6.2

2014

6.1

2005

6.4

1961

7.2

1942

7.0