1992

6.5

2009

5.8

1998

5.5

2008

5.3

1977

6.8

2008

4.1

1999

6.3

1992

3.3

1996

5.9

1994

6.2

1995

4.7

2007

6.3

2014

3.7

2018

7.1

2002

4.4

2019

8.0

2005

6.0

1997

6.1

1998

6.1

2001

6.7