Of the black officers, how many of them investigated cases between the years 2010 and 2015?
black refers to race = 'B'; between the years 2010 and 2015 refers to date between '2010-01-01' and '2015-12-31'; case refers to case_number
SELECT COUNT(T1.case_number) FROM officers AS T1 INNER JOIN incidents AS T2 ON T2.case_number = T1.case_number WHERE T1.race = 'B' AND T2.date BETWEEN '2010-01-01' AND '2015-12-31'
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)
);
