What are the least Top-5 finish when the events are greater than 18?
CREATE TABLE table_42615 (
    "Tournament" text,
    "Wins" real,
    "Top-5" real,
    "Top-10" real,
    "Top-25" real,
    "Events" real,
    "Cuts made" real
)
SELECT MIN("Top-5") FROM table_42615 WHERE "Events" > '18'
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: What are the least Top-5 finish when the events are greater than 18? ### Input: CREATE TABLE table_42615 (
    "Tournament" text,
    "Wins" real,
    "Top-5" real,
    "Top-10" real,
    "Top-25" real,
    "Events" real,
    "Cuts made" real
) ### Response: SELECT MIN("Top-5") FROM table_42615 WHERE "Events" > '18'