1960

7.4

1997

7.5

2012

5.9

2009

7.1

2007

7.2

2008

5.8

1988

7.1

2004

7.3

1987

6.8

2004

5.4

1981

6.5

2003

6.6

1987

6.8

1995

4.9

2023

7.0

1997

7.1

2019

5.0

1989

6.2

2006

5.5

1999

6.5