1958

7.4

2002

6.3

1994

7.5

1977

7.7

1990

6.1

1979

2.3

2006

7.0

1993

7.0

2007

5.4

1988

6.7

2004

6.8

1996

6.6

2005

5.8

1998

6.0

1996

5.9

2003

6.5

2003

6.4

2007

4.8

1979

7.1

2005

6.7