1990

5.8

2014

5.4

1966

6.3

2008

6.6

2007

6.2

1961

7.2

1984

7.3

1975

6.9

1955

7.1

1972

6.2

2000

5.2

2004

6.7

2005

5.7

2010

6.3

2018

6.6

1966

7.3

2008

6.4

1994

6.2

2012

5.2

2010

5.8