1981

6.2

1987

6.0

2000

5.8

1999

7.0

1985

6.6

1996

7.0

2000

6.1

1988

4.9

2005

6.8

2022

7.1

1965

6.2

2020

7.2

2017

4.0

1982

7.2

2001

6.8

2000

6.2

2008

5.4

2002

4.3

1985

6.3

2017

6.4