1950

6.8

2001

5.9

2002

5.3

1993

5.7

1981

6.2

2007

7.4

2007

6.6

1968

6.3

1964

7.2

1927

7.1

1967

7.1

2002

6.9

2008

5.4

1962

5.6

2002

7.4

1966

7.3

1991

7.2

2006

6.3

2002

4.5

1960

7.3