1988

5.0

1999

7.4

2003

5.9

2013

6.7

1996

6.6

2002

7.1

2005

6.3

2009

4.5

1999

6.8

1998

6.6

2002

7.2

1995

3.3

1995

6.7

1993

5.5

1990

5.7

1990

4.2

1960

6.1

2013

4.9

1994

7.0

2005

6.8