1993

6.3

1991

6.7

1984

6.0

2002

6.2

1997

6.8

2005

6.7

2007

6.5

1989

7.0

1995

7.0

2016

6.5

1999

7.6

2017

6.1

1999

6.5

2001

1.3

2003

5.5

2006

5.8

1985

4.5

2000

5.9

2004

7.2

2000

7.6