1969

6.9

1979

7.6

1999

6.1

2006

7.4

1992

7.7

2018

6.6

1980

8.2

1999

6.2

1999

6.8

2012

6.3

2019

8.1

2014

7.1

2004

8.1

1995

6.9

2017

6.7

2012

6.2

1966

8.5

1993

4.9

1993

7.8

2006

5.8