1971

4.0

2013

6.1

2021

5.7

2024

4.8

2008

5.7

2006

6.1

2014

5.6

2015

6.6

2016

6.7

2012

5.7

2013

6.1

6.4

2000

5.1

2002

7.5

1971

6.8

2017

6.9

2024

7.2

1975

4.5

7.3

1980

6.6