1994

5.9

2007

5.3

2000

5.0

2001

5.8

2005

6.8

1998

6.3

2008

4.0

1997

6.1

1989

3.0

1976

4.7

1999

7.3

2014

5.0

1984

6.0

1996

5.5

2004

5.7

1990

4.0

1991

3.9

1982

6.4

1981

6.9

1986

6.4