1964

5.5

1966

6.5

2005

5.9

2000

7.0

1969

7.1

2017

7.3

1994

7.5

2009

6.3

2003

7.4

2006

6.4

2011

4.0

1968

5.0

1978

6.4

1983

6.6

2014

6.3

1974

6.4

2005

7.4

1998

7.4

2019

7.2

2009

5.8