1968

7.1

1985

5.6

2007

5.8

2007

1.0

1985

6.6

2007

6.7

1996

6.8

2004

5.1

1995

7.2

6.0

1998

8.1

1990

7.0

1992

8.4

1973

7.0

1977

6.4

1967

7.4

2003

7.3

2001

6.4

2006

7.0

2004

6.2