1975

5.5

1988

7.1

1976

5.6

2002

6.3

2003

7.8

1968

7.6

2006

7.4

2009

7.0

2000

3.7

1992

5.0

2009

6.5

2014

6.2

1964

4.4

1999

4.8

1995

3.8

2018

4.4

1977

5.6

2007

5.9

1971

5.2

2004

1.5