How many figures are named for security forces in 1998?
CREATE TABLE table_24520 (
    "Period" real,
    "Civilians" text,
    "Security forces" text,
    "Insurgents" text,
    "Total per period" real
)
SELECT COUNT("Security forces") FROM table_24520 WHERE "Period" = '1998'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How many figures are named for security forces in 1998? ### Input: CREATE TABLE table_24520 (
    "Period" real,
    "Civilians" text,
    "Security forces" text,
    "Insurgents" text,
    "Total per period" real
) ### Response: SELECT COUNT("Security forces") FROM table_24520 WHERE "Period" = '1998'