1997

7.8

1992

6.8

1968

6.7

1998

5.5

1995

6.5

2004

7.2

2014

4.3

1992

8.1

1954

8.0

1995

5.2

1989

6.0

2017

4.7

2007

6.7

1990

5.7

2000

4.8

1970

5.0

2005

5.4

1933

7.6

2003

8.1

1986

6.3