1997

4.7

2005

6.3

2014

6.5

2009

4.8

2006

5.7

1996

4.5

1990

6.1

1989

7.0

1990

7.4

1982

5.8

2010

7.1

2021

7.7

2008

6.9

2008

5.5

1947

6.7

2020

6.4

2009

7.3

1985

5.6

1988

6.0

2011

7.0