1980

6.4

1990

6.8

2001

5.7

2017

5.2

2019

8.0

1987

8.0

1977

7.9

2011

6.3

2018

6.2

2001

6.0

2007

6.7

1998

7.0

2022

6.8

1995

6.6

2009

7.0

2006

4.3

1991

7.5

1999

7.1

2005

6.6

2004

7.1