1966

6.4

1995

5.4

1997

4.4

1997

7.2

2002

6.4

2002

7.3

2004

7.3

2007

6.4

2005

7.1

2008

8.5

2005

7.5

2004

4.6

1999

4.5

1992

6.9

2016

6.5

1989

7.2

2005

7.7

2019

7.0

2016

7.7

1996

6.4