Division

I am having a problem gettig a percent via division. Below is the first
part of my trigger function where pct returns 0.00, instead of the
expected 0.50. If I try without dimensions to the numeric variable, I
just get 0. What is the correct way to accomplish the percent?

CREATE OR REPLACE FUNCTION "public"."issue" (varchar) RETURNS numeric
AS'
DECLARE
  repar text[];
  pct numeric(3,2);
  noreps integer;

BEGIN
  repar := string_to_array($1,''-'');
  noreps := array_upper(repar,1);
  pct := 1/noreps;
  RETURN pct;
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

bachman=# select issue('AA-BB');
 issue
-------
  0.00
(1 row)