1990

4.5

1997

6.8

2008

6.2

1998

5.8

2014

4.3

2000

7.3

2002

6.1

2007

6.6

2004

6.6

2000

6.3

2024

5.4

2018

5.3

1988

7.7

2014

5.8

1971

7.4

1984

6.2

2004

7.1

2020

5.5

1977

8.2

1996

4.3