1993

6.1

2015

5.9

6.3

2014

6.8

2012

6.4

2017

6.0

2007

7.0

1982

5.9

2019

6.3

1968

6.9

2004

6.7

2016

7.5

2002

8.5

2009

6.2

2012

9.4

2009

6.5

2011

7.4

2021

7.1

1988

5.5