1992

6.2

1982

6.7

1975

6.3

2001

7.8

1999

7.0

1991

6.2

2002

5.7

1997

6.9

2002

5.3

2001

5.9

1946

7.6

1968

7.1

1979

7.2

2002

6.7

1996

5.6

1936

6.1

2002

6.3

1999

5.4

2014

6.5

1964

7.8