1993

6.2

2014

5.9

2015

6.4

2020

5.8

2007

5.4

2013

6.1

1975

4.5

2016

7.0

2006

6.3

2019

6.0

2010

7.2

2017

6.4

2018

9.8

1997

6.3

2017

6.4

1978

4.4

2012

5.7

1995

6.6

2024

5.6

1968

6.4