1996

5.2

1995

5.2

2019

6.4

2005

6.5

1980

7.0

1983

6.2

2004

7.1

2008

6.1

1987

7.3

1999

5.4

2008

6.3

2007

6.1

1990

5.6

2000

6.8

1986

6.2

1973

6.5

1975

6.1

1978

6.1

1996

5.9

2001

5.9