2003

5.8

2010

7.1

2009

5.7

2003

5.0

2000

6.3

1999

6.1

2010

6.1

2009

7.1

1972

6.2

2012

6.4

2009

6.6

1991

7.0

2021

7.7

2014

4.4

2014

6.8

2010

4.8

1981

6.0

1984

6.7

2015

7.9

2013

7.5