1987

6.5

1978

7.2

2016

7.9

1993

6.2

2002

5.3

2001

6.3

2004

7.0

1982

6.6

1968

7.2

1995

7.9

2000

6.4

2006

4.4

2001

5.9

1997

6.1

1999

7.3

2005

3.2

2001

5.5

2014

5.5

1995

5.1

1988

6.3