1997

6.4

2003

5.1

1975

6.8

2008

6.1

1977

6.8

2004

6.6

2019

6.4

1996

6.8

2004

5.9

2002

6.4

1989

5.8

1987

7.1

1981

6.4

1957

7.0

2009

7.2

1978

6.3

1986

6.2

1968

5.7

1978

5.3

2007

6.9