1975

7.1

2004

9.9

2018

6.5

2015

6.4

2009

6.2

5.3

1985

6.1

2015

6.7

6.6

1999

7.5

2010

7.4

1985

6.9

1968

7.5

2002

9.1

1981

5.8

2011

5.6

2020

7.6

2018

5.9

2023

6.3

2012

7.2