1997

1.0

1989

3.1

1970

2.0

2006

7.4

2004

5.5

2013

6.7

2019

6.9

1988

7.1

2001

5.1

1968

7.6

2003

7.8

1989

5.0

1976

5.7

1993

7.8

2002

5.6

2012

4.4

1975

5.5

2009

6.5

1999

4.8

2007

6.0