2000

8.2

1982

7.9

1994

8.3

1976

8.1

1998

7.8

2008

8.5

1997

7.4

2005

7.5

2014

6.4

2003

5.8

1992

6.9

1958

8.2

2005

7.0

1988

5.6

1981

5.1

2007

6.4

1968

6.1

1992

5.5

1984

6.0

1981

7.4