1975

7.8

1992

6.8

2007

6.4

2002

5.3

1994

7.3

1994

5.9

2004

7.2

1993

6.2

1996

6.3

2001

6.3

1995

6.0

1996

6.1

2019

6.6

2005

7.1

2006

7.1

1974

6.6

2000

6.7

2002

6.2

2017

5.5

1996

5.7