1998

6.9

2006

6.7

2005

7.7

1999

6.8

2006

6.9

2003

7.2

2002

6.6

2006

6.4

1952

5.3

1939

7.2

1946

7.4

2002

7.3

1991

6.3

1968

4.2

1996

6.7

2003

6.6

1973

7.5

1949

6.1

2016

10.0

2006

8.2