1998

7.3

2005

6.0

2013

6.7

2006

7.6

2017

6.8

2008

5.9

2016

6.5

2007

6.6

1978

7.5

2000

7.4

2001

5.8

2006

6.0

2008

5.6

1985

8.3

2020

1.0

1995

7.7

1992

7.0

2020

4.8

2002

6.2

2006

6.3