1997

7.2

2002

6.4

2001

7.9

1991

6.2

1990

6.7

1993

5.5

2001

7.1

2023

8.0

1967

6.5

2012

7.3

1996

6.4

1994

7.0

1974

4.7

1986

6.8

1976

7.3

1996

5.9

1999

5.5

2006

5.6

2003

5.6

1999

6.5