1974

5.8

1991

5.1

1993

6.2

2002

6.1

1982

7.2

1984

4.8

1998

5.0

2009

6.7

2002

5.5

2008

4.8

2003

5.8

1990

4.7

2000

6.3

1999

5.2

2007

5.4

2017

7.3

2004

5.8

1986

6.3

2003

5.6

1976

5.7