1980

8.2

2005

6.3

1985

4.3

1998

7.1

1990

7.0

1997

7.6

2021

5.0

1975

4.1

2006

7.0

1986

7.6

2017

6.2

2007

5.2

2008

5.5

2001

7.8

1999

7.1

2010

6.0

1987

6.9

1985

7.5

2000

6.3

2005

5.6