2005

6.7

1995

6.0

1999

6.8

2007

7.6

2007

5.2

2020

6.4

2007

7.3

1975

6.3

1974

5.9

2011

3.8

1998

7.1

2006

7.6

2006

5.4

1993

6.7

2000

6.0

1997

6.5

2006

5.1

2002

7.0

2007

7.1

1965

6.9