1993

6.6

2002

6.8

1985

5.7

2003

5.5

2003

6.7

1996

7.3

1974

6.6

1986

6.1

1999

6.3

2001

5.4

1990

7.5

1968

7.5

1999

6.3

1999

6.2

2004

6.3

1991

6.2

2001

5.8

2000

5.7

1996

6.6

1993

6.6