1927

8.1

1985

8.3

2001

6.2

1991

5.7

1960

7.3

2002

6.2

1998

5.4

1956

6.6

2004

6.9

2006

7.6

2008

5.6

2006

6.5

1993

6.7

2006

5.7

2004

6.2

1994

6.3

2000

4.9

2017

4.9

2001

7.1

2003

6.2