1984

6.2

1998

8.2

1990

7.3

2009

6.5

2000

4.8

1986

6.9

1991

4.7

1994

4.7

2002

5.6

2014

3.1

1997

6.3

2005

5.4

1991

8.1

2013

6.4

2008

4.7

1977

7.2

2007

5.3

2010

6.7

1998

6.4

2006

5.1