1987

6.0

1993

5.4

1999

7.1

1987

6.8

1971

7.2

1993

6.0

2003

5.6

1993

6.5

2001

6.0

2006

4.2

1990

5.1

2007

3.9

2004

6.2

1999

5.8

2018

2.0

2008

5.3

1974

7.2

1995

6.1

1988

5.7

1967

5.3