1984

2.5

2010

2.5

2020

7.8

2008

4.7

2000

7.4

1964

5.8

2003

6.5

1999

5.4

1986

3.0

1993

0.0

2004

6.4

1994

7.3

2015

0.0

2016

3.5

2010

4.5

2013

5.0

2016

6.8

1981

8.5

2014

6.0

1997

6.8