2020

6.2

2004

6.3

2006

5.4

2006

6.6

2008

4.0

1999

7.1

2006

7.2

1975

3.8

1975

5.8

1997

6.6

2006

5.0

2007

6.7

1992

7.4

2001

6.4

2004

3.1

1970

4.0

1970

4.5

1968

5.4

2007

7.4

1969

5.5