2007

6.6

2005

6.4

1998

6.3

2014

7.2

2002

6.2

2005

6.5

2005

6.2

1998

6.5

1977

6.3

2005

6.7

1999

5.4

1972

6.9

1973

7.8

2004

6.9

2003

6.3

2003

4.9

1992

1.9

1986

7.5

2002

4.7

1969

6.9