1999

5.4

2006

7.0

1984

6.0

2002

6.7

2007

6.4

2007

6.7

1996

5.6

2001

6.1

1969

7.0

1994

5.7

2003

6.1

1973

6.4

1975

5.7

2007

6.3

1972

5.0

1992

5.7

1997

6.4

2004

6.9

1965

6.3

1973

7.5