1984

5.9

1988

7.0

2004

7.3

1994

7.0

1991

6.8

2007

6.2

1979

6.0

2019

6.1

2016

6.0

1998

5.0

1961

6.0

1985

5.4

2002

7.4

2007

7.6

2005

6.3

2007

5.4

1990

5.2

2014

6.0

2019

8.0

2011

4.0