1988

6.4

1987

6.7

2003

5.7

1997

6.1

2007

6.0

2018

6.2

2016

4.7

2020

1.0

2016

5.6

1986

5.0

1958

5.7

1984

4.2

2007

3.6

2017

4.9

2009

3.9

2017

5.2

1973

6.1

2017

5.5

2019

4.1

2009

6.1