2003

3.9

1963

7.1

1967

6.6

1981

6.5

1991

8.1

2005

6.7

1987

6.5

1968

7.6

2010

6.5

2005

4.8

1974

6.4

1985

6.2

1996

6.2

1991

6.8

1981

7.4

1997

6.6

1998

6.3

1973

5.7

2007

6.7

2006

5.2