How many more black female victims than white female victims were discovered?
black refers to race = 'B'; female refers to gender = 'F'; white refers to race = 'W'; result = subtract(count(victims where race = 'B'), count(victims where race = 'W')) where gender = 'F'
SELECT SUM(race = 'B') - SUM(race = 'W') FROM subjects WHERE gender = 'F'
CREATE TABLE incidents
(
    case_number                TEXT  not null
        primary key,
    date                       DATE          not null,
    location                   TEXT  not null,
    subject_statuses           TEXT  not null,
    subject_weapon             TEXT  not null,
    subjects                   TEXT  not null,
    subject_count              INTEGER           not null,
    officers                  TEXT not null

);
CREATE TABLE officers
(
    case_number TEXT not null,
    race        TEXT         null,
    gender      TEXT         not null,
    last_name   TEXT not null,
    first_name  TEXT null,
    full_name   TEXT not null,
    foreign key (case_number) references incidents (case_number)
);
CREATE TABLE subjects
(
    case_number TEXT not null,
    race        TEXT         not null,
    gender      TEXT         not null,
    last_name   TEXT not null,
    first_name  TEXT null,
    full_name   TEXT not null,
    foreign key (case_number) references incidents (case_number)
);
