1970

7.1

2002

7.3

2017

6.8

1990

8.5

1997

7.6

1989

7.0

1989

7.2

2001

6.0

2004

6.3

1989

7.1

2006

6.6

1995

8.0

1972

7.8

2005

7.1

1984

7.5

1972

7.1

1970

7.2

1979

7.0

2014

5.6

2011

4.9