1990

5.8

1994

6.5

2000

8.2

2012

9.4

2006

6.9

1996

7.9

2011

5.9

1982

6.9

2011

7.0

1995

7.7

1996

7.7

1998

6.0

1977

7.7

1997

7.6

2020

7.3

1997

6.9

2000

7.1

2003

7.8

1995

8.0

1979

7.7