1964

7.0

1963

6.8

1954

7.6

1967

5.7

1991

6.0

1990

4.4

1997

6.5

2009

5.6

2016

6.1

1992

5.7

2000

6.4

1964

7.0

2009

6.0

2002

7.4

2016

6.9

1971

6.8

2010

6.6

1966

6.3

2012

5.1

2008

6.2