1968

6.9

2004

7.1

1971

6.7

2003

6.2

1993

6.1

2009

6.6

2020

5.5

2014

4.8

1951

7.8

2018

7.8

2004

7.0

2004

5.7

1988

6.6

1984

6.1

2017

4.2

1986

7.2

2001

7.5

2013

6.8

2005

5.6

1993

7.9