1988

5.2

2012

4.8

2016

5.9

2021

6.6

2001

8.9

2018

6.4

2012

7.3

1996

6.3

1998

6.1

1996

6.5

2007

7.3

1984

7.1

2015

5.7

2010

6.3

1970

6.3

2021

6.9

2014

8.4

2017

6.7

2021

6.8

1989

6.3