1969

6.0

1999

5.6

1996

6.4

1976

7.6

1973

6.9

1993

6.4

2006

6.3

1972

7.1

1988

7.8

1956

7.7

1968

7.8

2004

6.5

2019

5.6

2021

6.2

2005

6.7

1981

7.2

1991

7.6

1994

6.4

2005

6.4

2008

5.4