1973

8.1

2007

7.3

2013

7.5

1998

7.2

2015

7.1

2013

6.7

1989

7.9

1993

6.3

2021

7.0

2004

8.1

2013

5.3

1999

5.8

2000

8.1

2004

7.5

2010

8.0

2016

7.7

1993

8.2

1993

5.2

2005

6.8

2007

6.2