1982

7.5

2005

6.3

1990

7.4

2000

6.0

2017

5.9

2016

4.8

2005

7.2

1995

7.6

1982

6.7

2006

7.9

2003

8.3

1976

6.0

2016

5.7

1987

4.1

2005

7.1

2004

6.5

2017

6.2

2006

6.7

2002

7.2

2021

6.6