1990

7.4

1989

6.5

1998

7.8

1974

5.0

0.0

2005

7.0

1993

7.9

1986

6.8

1998

7.1

1973

6.9

1982

7.1

2000

8.1

1998

6.9

2004

6.2

1992

6.7

2001

5.0

1996

8.1

2007

7.6

2006

6.0

1997

7.3