1985

6.8

1997

6.9

1986

6.1

1989

6.1

1988

6.1

1985

7.1

2003

6.1

2002

6.2

1993

6.0

1996

5.7

1990

6.0

1996

5.4

1988

6.1

1990

6.1

2012

4.9

2005

5.8

2003

6.8

1988

7.1

1991

6.6

2002

3.7