1954

6.8

1961

6.5

2005

6.9

1964

7.0

1997

7.1

1997

6.1

2007

6.9

1989

6.3

2007

6.0

1977

6.6

1994

4.8

1977

4.9

1976

4.9

1956

6.5

1993

5.7

2006

2.2

1959

4.3

2002

5.5

1998

6.2

1958

6.1