1988

5.6

2004

6.3

2007

6.8

2000

5.5

1977

5.2

1975

7.3

2014

6.0

2011

7.2

2018

6.1

1969

5.5

1998

5.7

2006

5.8

2016

7.0

2020

9.0

2011

5.6

2012

6.1

2018

7.5

2009

4.6

2008

7.4

2018

4.9