1980

6.3

2001

6.2

2007

7.4

2004

5.9

2017

6.9

1994

6.8

1975

5.9

2004

5.0

1990

5.7

2008

4.9

2008

5.2

2025

7.5

1961

8.1

2002

5.4

1994

6.0

2018

6.3

1993

7.0

2004

7.5

2002

4.1

2006

6.5