1991

6.9

1968

8.1

2001

8.4

1988

6.4

2018

7.4

1994

8.5

1989

8.3

2015

7.6

2004

7.5

1985

7.2

2017

7.3

1994

8.5

2016

6.8

2016

7.3

2016

6.7

2016

7.9

2014

8.5

1986

5.6

1995

7.2

2018

8.0