1986

6.9

1987

6.6

1989

7.2

1987

8.1

1986

7.7

2001

7.4

1991

5.6

2005

6.2

2001

6.4

2000

8.2

1930

7.8

1925

7.6

1998

5.7

2003

6.2

1993

7.3

2014

6.8

2008

6.1

1935

6.5

2008

4.8

1986

6.0