1969

7.8

1988

7.6

1979

7.5

1961

7.0

2000

7.8

1992

7.2

2006

9.3

1967

7.4

2016

7.0

2013

6.9

2017

7.2

1981

6.9

2011

8.6

1997

7.1

2002

7.9

1972

7.7

2010

7.6

1990

6.1

1993

7.4

2006

8.2