in which years did civallero only have one achievement ?
CREATE TABLE table_203_734 (
    id number,
    "year" number,
    "competition" text,
    "venue" text,
    "position" text,
    "event" text,
    "notes" text
)
SELECT "year" FROM table_203_734 GROUP BY "year" HAVING COUNT(*) = 1
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 which years did civallero only have one achievement ? ### Input: CREATE TABLE table_203_734 (
    id number,
    "year" number,
    "competition" text,
    "venue" text,
    "position" text,
    "event" text,
    "notes" text
) ### Response: SELECT "year" FROM table_203_734 GROUP BY "year" HAVING COUNT(*) = 1