1981

6.7

2003

8.3

1994

8.5

1999

8.4

2008

8.5

2010

8.4

1994

8.7

2000

8.2

2006

7.4

2014

7.3

2019

8.2

1988

7.5

2013

7.9

2005

7.7

1998

6.6

1993

8.6

1999

8.2

1941

8.0

2015

7.5

1985

8.3