2002

6.2

1999

5.2

1996

5.6

2016

6.5

1981

6.6

1988

7.0

2006

7.2

2003

6.0

2003

5.1

1987

6.8

1975

7.2

1981

6.5

1990

6.8

2005

6.3

2006

0.0

2004

6.8

1975

10.0

1960

6.0

2017

0.0

1985

7.0