2010

3.6

2005

5.8

1989

5.3

1992

5.7

2010

7.1

2008

7.6

2003

5.3

1989

7.9

1993

4.8

1999

7.4

2017

6.2

1991

7.0

1961

8.4

2012

6.4

2000

6.1

2014

6.8

2008

7.0

2017

6.5

2020

6.5

2017

7.8