1997

7.6

1976

8.1

1993

7.7

1994

7.5

2013

1.5

1992

6.5

1995

7.0

1999

7.5

1969

7.1

1971

7.0

1996

7.0

1996

7.5

1999

5.5

2008

6.3

2008

5.9

1979

6.4

2014

6.0

2017

4.0

2007

5.6

2004

5.0