ADDOBS distname val1 [number1] val2
[number2]; where distname is a label used to identify this added
observation. val1 and number1 refer to the vote proportion and
vote weight, respectively. val2 and number2 set the number of
seats (usually 0 or 1) and the seat weight, respectively. number1 is
used only if WT VOTES has been specified previously and number2 is used
only if WT SEATS had been declared first. Any of these may be listed as
missing by using a `.' in place of one of the values.
Gary King
2006-01-07
