1986

6.8

1982

6.9

2010

8.2

2005

6.6

1990

5.8

1995

5.0

1985

8.3

2000

8.2

1995

8.0

1987

7.3

2004

8.1

1997

7.9

1959

8.1

2003

7.0

1958

6.9

1993

6.7

2011

6.5

1999

5.6

1999

8.0

1959

6.9