1981

5.2

1990

6.0

1993

3.0

2005

5.3

2008

9.5

2015

7.5

1995

2.0

2020

5.2

1994

7.0

1993

6.0

2018

8.0

1999

5.5

1996

0.0

2003

6.7

2001

6.2