BEGIN

    FOR r_company IN (
        SELECT
            ID,total_emps,bank
        FROM
            companies
        WHERE
            turnover > 100000
    ) LOOP

        INSERT INTO 
            my_table
        SELECT
            score
        FROM
            ref_table
        WHERE
            ref.total_emps = conversion_func( r_company.total_emps )
        ;

    END LOOP;

END;
/