1994

7.5

1994

7.6

2004

8.0

2003

7.4

2014

6.3

1978

7.1

1970

7.6

1993

7.9

1999

8.4

1981

8.0

1999

6.6

2005

7.5

2006

8.1

1995

7.0

1998

7.1

1972

8.1

2000

7.4

1997

7.3

1983

5.2

2007

7.0