Calculate the average number of female students who are disabled and who joined Foreign Legion organization.
average = DIVIDE(COUNT(disabled.name who are not in male.name WHERE organ = 'foreign_legion'), COUNT(disabled.name)); female students who are disabled refers to disabled.name who are NOT in male.name; organization refers to organ; organ = 'Foreign Legion';
SELECT CAST(SUM(IIF(T3.name IS NULL, 1, 0)) AS REAL) / COUNT(T1.name) FROM disabled AS T1 INNER JOIN enlist AS T2 ON T1.name = T2.name LEFT JOIN male AS T3 ON T2.name = T3.name WHERE T2.organ = 'foreign_legion'
database name:db_id student_loan
bool table bool Cols: name dtype text, 
person table person Cols: name dtype text, 
disabled table disabled Cols: name dtype text, 
enlist table enlist Cols: name dtype text, organization dtype text, 
filed_for_bankruptcy table filed_for_bankruptcy Cols: name dtype text, 
longest_absense_from_school table longest_absense_from_school Cols: name dtype text, month dtype integer, 
male table male Cols: name dtype text, 
no_payment_due table no_payment_due Cols: name dtype text, bool dtype text, 
unemployed table unemployed Cols: name dtype text, 
enrolled table enrolled Cols: name dtype text, school dtype text, month dtype integer, 
