2010

4.4

2015

5.3

1992

6.9

1968

7.3

2009

6.7

2015

6.2

2002

7.5

1973

5.7

2020

6.8

2019

5.0

2005

6.4

2019

7.1

2015

7.0

1997

5.1

2016

5.9

2008

7.4

1989

7.2

2015

5.8

1975

5.4

2004

7.3