1958

7.5

1996

7.7

2000

8.2

2006

7.8

1998

7.9

1979

7.7

2003

7.6

2015

8.4

2003

7.4

1999

8.2

1995

7.6

2020

8.7

2007

8.3

2011

7.7

2005

7.0

1980

6.5

1998

7.0

2018

7.8