1962

6.9

1964

7.0

1979

5.6

2001

6.4

2005

7.7

1999

6.7

1995

5.8

2006

6.9

1993

5.5

2004

5.9

2000

7.2

1976

0.0

2014

4.8

2005

6.1

1955

6.0

1973

6.8

1942

5.7

1968

6.9

2000

7.3

2017

7.0