1964

7.4

1979

7.3

1985

6.1

2006

5.0

1969

7.1

1986

5.8

2011

5.8

1984

7.1

1985

6.2

1997

6.1

1998

4.8

2008

5.7

2003

5.7

1989

6.2

2003

5.7

2001

6.0

1990

6.4

2019

5.7

2008

6.7

2023

7.0