1987

6.8

2000

4.4

2014

6.7

1986

5.9

2007

6.1

2006

5.9

2006

6.5

2017

6.3

1978

6.3

2005

4.3

1998

7.5

1995

7.3

1980

5.7

1971

6.7

1984

5.4

1993

5.3

2003

6.6

1992

6.0

2000

5.0

2004

7.3