1990

7.3

2018

8.2

2017

7.0

1998

6.8

1994

8.7

2001

7.9

2016

7.4

2015

6.9

1998

7.8

1990

6.1

2016

7.6

2017

7.5

2010

7.1

2003

8.0

2016

7.0

2011

5.5

2012

7.4

2016

7.1

1969

7.1

2005

7.0