1995

8.2

2003

8.3

1994

8.5

1995

7.9

1971

7.4

2001

7.8

1999

7.0

1999

7.1

2013

6.8

2016

6.0

1993

4.0

1986

5.8

1971

7.0

1975

6.5

2017

7.1

2006

6.9

2003

5.8

1997

4.0

2007

6.8

1987

6.4