1992

6.3

1997

5.7

1986

7.0

2005

6.8

1974

7.5

2002

5.4

2003

5.5

1973

6.0

1997

6.5

1999

6.1

1997

6.8

1987

3.0

1998

7.1

1989

6.2

1982

5.2

1996

6.4

2014

6.3

2003

6.8

1993

7.4

1986

5.8