2000

5.5

1998

6.0

1989

5.7

2007

6.2

2013

5.9

2017

6.8

2021

6.1

2015

5.2

2003

5.8

2011

6.9

1984

6.6

2010

7.9

2010

6.2

1974

6.8

2015

6.2

2011

5.7

2014

7.7

2016

7.6

2009

5.3

2015

6.0