1992

5.3

2009

5.4

2014

4.6

2011

6.1

1968

6.5

2014

6.7

1979

4.7

1975

6.9

1991

7.3

1895

6.8

1996

6.0

1989

7.4

1957

8.1

2011

5.5

1990

7.4

2008

7.6

1980

6.5

1965

8.0

2005

6.7

2003

6.3