2017

6.3

2001

6.5

1970

6.4

1990

7.4

1996

6.6

2006

8.2

1997

6.4

1993

7.1

1994

6.2

1993

7.7

2007

7.3

1996

6.0

1984

7.2

1984

5.9

1979

6.8

1986

7.1

1992

6.2

1995

7.2

1994

7.0

1999

7.8

1989

8.0

1996

7.8

1995

4.1

1997

4.1

1997

6.0

2005

8.3

2006

7.3

2005

6.9

1996

3.5

2008

5.7