1998

6.2

2010

6.6

1965

6.8

1974

7.0

1992

5.0

2013

7.3

1955

7.2

2011

6.9

1964

7.0

2013

8.0

2002

7.1

2014

7.7

2007

7.4

1972

6.4

1987

4.5

2017

6.8

2013

7.7

2017

7.4

1975

6.9

2012

6.3