1964

6.1

1993

5.7

2007

6.3

2006

7.2

2006

7.0

1994

6.7

1995

5.6

2003

7.1

2001

6.6

1987

6.8

2005

6.0

2021

4.0

1996

7.5

2006

5.1

1968

7.5

1973

7.5

1957

5.4

1991

6.4

2004

5.2

1998

7.2