1977

6.0

1971

7.1

2015

6.8

1997

4.6

2005

6.5

1998

6.8

2004

6.5

2006

5.9

1972

7.1

1996

6.5

1985

6.2

2006

7.1

2016

7.3

1996

6.3

1979

4.7

2000

6.5

2003

5.8

1997

6.2

2006

5.3

1996

6.1