1998

6.7

1993

5.4

1997

6.2

2000

6.6

1993

7.6

2008

5.3

1989

6.0

1991

6.0

1995

6.2

1992

3.5

1987

4.2

1973

7.3

1995

4.7

1990

5.5

1953

5.6

1996

5.3

2013

7.6

1971

4.0

2013

6.1

1985

1.0