1988

5.3

2014

6.0

2017

5.5

2019

6.7

2018

7.5

1999

5.7

1968

5.7

2013

5.7

2012

7.8

2016

6.8

1992

7.3

2016

6.8

2016

6.4

2019

6.2

2020

7.3

2004

5.9

1973

5.0

2024

6.5

2006

6.6

2015

5.4