2001

6.8

2000

7.1

1988

6.3

2006

5.4

2007

5.2

2006

5.1

2002

5.6

2000

6.1

1983

6.4

1977

6.0

2000

5.1

1973

7.4

2002

6.7

1996

5.6

1999

5.7

2001

7.3

2002

6.3

2015

4.2

1993

6.8

2007

5.2