1993

6.7

2004

6.4

1997

7.1

1997

6.6

2005

6.5

1980

6.9

1983

6.2

1992

7.5

2007

7.5

1990

5.8

2004

7.1

2003

7.3

1977

6.9

1998

6.2

2017

5.7

2018

10.0

1986

6.5

1992

5.3

1996

5.5

2002

5.8