1990

6.9

2011

6.4

2017

7.9

1997

7.4

1968

8.5

2001

7.2

2012

6.8

1972

8.0

2016

7.5

2023

6.3

1976

7.0

2016

7.2

2012

8.2

7.5

2021

6.7

1975

5.0

2004

10.0

2018

8.8