1970

7.1

1964

7.1

1988

6.3

2005

5.3

1994

7.5

2014

6.7

1980

6.6

1996

6.4

2001

7.3

2002

6.8

1986

6.1

1997

6.0

2009

6.6

2007

4.0

2017

6.9

2007

3.0

2017

5.0

2010

3.9

2022

1.0

2003

5.3