1998

6.0

2005

5.1

2008

6.2

1988

6.6

2008

1.0

1981

0.0

1963

7.0

1981

7.2

1985

4.1

2007

5.6

2006

5.3

2004

5.5

2000

3.8

2017

6.7

2011

8.0

1989

6.5

2017

2.0

2016

0.0

2017

8.0

1999

7.6