1985

6.3

1988

6.8

1991

5.8

1987

4.9

2008

6.3

2000

6.4

2005

6.8

2003

6.6

2013

4.9

1998

6.0

2015

7.2

2006

6.0

2007

6.9

2014

4.0

2001

6.7

2001

5.9

2018

7.0

2002

4.0

1988

7.2

2015

6.0