1969

5.1

1972

6.4

1967

6.5

1966

6.3

2008

6.2

2009

4.1

2015

7.6

2000

7.2

2013

5.8

1966

6.4

1964

7.4

2000

5.1

2006

5.5

1982

8.1

1971

6.8

1979

6.2

2014

7.5

2015

6.2

2010

7.3

2013

6.5