When +18.1 is the yes side 2008 percentage what is the percentage of against?
CREATE TABLE table_20683381_3 (
    against___percentage_ VARCHAR,
    ±_yes_side_2008___percentage_ VARCHAR
)
SELECT against___percentage_ FROM table_20683381_3 WHERE ±_yes_side_2008___percentage_ = "+18.1"
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: When +18.1 is the yes side 2008 percentage what is the percentage of against? ### Input: CREATE TABLE table_20683381_3 (
    against___percentage_ VARCHAR,
    ±_yes_side_2008___percentage_ VARCHAR
) ### Response: SELECT against___percentage_ FROM table_20683381_3 WHERE ±_yes_side_2008___percentage_ = "+18.1"