1987

6.2

1991

6.6

2001

4.7

1928

6.9

1931

8.3

1965

7.5

2002

7.2

2001

7.0

1960

8.2

2000

5.9

1999

7.7

1971

7.6

1999

7.5

1986

7.6

2002

7.6

2004

8.0

2006

7.0

1999

5.4

1997

6.8

2016

5.0