In how many different years did schools located in Logan Township, Pennsylvania join the Conference?
CREATE TABLE table_23184 (
    "Institution" text,
    "Location" text,
    "Nickname" text,
    "Founded" real,
    "Type" text,
    "Enrollment" real,
    "Joined" real
)
SELECT COUNT("Joined") FROM table_23184 WHERE "Location" = 'Logan Township, Pennsylvania'
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: In how many different years did schools located in Logan Township, Pennsylvania join the Conference? ### Input: CREATE TABLE table_23184 (
    "Institution" text,
    "Location" text,
    "Nickname" text,
    "Founded" real,
    "Type" text,
    "Enrollment" real,
    "Joined" real
) ### Response: SELECT COUNT("Joined") FROM table_23184 WHERE "Location" = 'Logan Township, Pennsylvania'