1998

8.1

1999

6.9

2014

4.5

2006

5.0

2007

6.7

2002

5.6

2000

7.0

2005

6.2

2004

6.2

2002

6.3

1999

7.3

2001

6.7

2016

6.4

2005

6.0

2002

7.1

1980

7.3

2014

6.0

1996

2.5

1975

2.2

1999

6.4