2001

7.0

1922

7.7

1986

8.0

1979

6.2

1984

6.6

1993

6.1

1955

6.5

1996

5.8

1998

6.6

1965

5.7

1997

2.5

1985

6.6

1968

7.6

1989

5.7

1999

4.8

1999

7.9

2000

5.5

2001

5.1

2005

6.2

2008

5.6