2008

5.8

2000

6.4

1990

6.1

1998

6.1

1998

7.1

2006

5.9

1964

6.2

1999

6.0

1978

6.3

1984

6.1

1994

5.2

1965

6.1

1966

6.1

1964

6.3

1994

6.9

1994

6.2

1982

6.8

1970

7.5

1966

5.6

1997

5.3