1963

5.7

2001

7.8

2009

7.9

1997

7.0

1994

7.6

1996

6.8

2000

8.0

2016

7.0

1980

7.3

2020

8.7

2010

7.2

2009

8.4

1999

8.6

2017

5.9

2004

7.4

2006

7.5

2008

7.6

1975

6.7

1960

7.4

2010

7.4