When was the percentage of trains arriving within 5 minutes of scheduled time 89.6%?
CREATE TABLE table_171748_3 (
    period VARCHAR,
    _percentage_trains_arriving_within_5_mins_of_scheduled_time_moving_annual_average__maa_ VARCHAR
)
SELECT period FROM table_171748_3 WHERE _percentage_trains_arriving_within_5_mins_of_scheduled_time_moving_annual_average__maa_ = "89.6%"
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: When was the percentage of trains arriving within 5 minutes of scheduled time 89.6%? ### Input: CREATE TABLE table_171748_3 (
    period VARCHAR,
    _percentage_trains_arriving_within_5_mins_of_scheduled_time_moving_annual_average__maa_ VARCHAR
) ### Response: SELECT period FROM table_171748_3 WHERE _percentage_trains_arriving_within_5_mins_of_scheduled_time_moving_annual_average__maa_ = "89.6%"