system: You are a text-to-SQL generator. Given a database schema and a question, reply with a single valid SQLite query that answers it. Output only the SQL on one line, with no explanation and no markdown.

user: Schema:
CREATE TABLE Attributes (
  attribute_id integer PRIMARY KEY,
  attribute_name text
);
CREATE TABLE Categories (
  category_id integer PRIMARY KEY,
  category_name text
);
CREATE TABLE Compliments (
  compliment_id integer PRIMARY KEY,
  compliment_type text
);
CREATE TABLE Days (
  day_id integer PRIMARY KEY,
  day_of_week text
);
CREATE TABLE Years (
  year_id integer PRIMARY KEY,
  actual_year integer
);
CREATE TABLE Business_Attributes (
  attribute_id integer PRIMARY KEY,
  business_id integer PRIMARY KEY,
  attribute_value text
);
CREATE TABLE Business_Categories (
  business_id integer PRIMARY KEY,
  category_id integer PRIMARY KEY
);
CREATE TABLE Business_Hours (
  business_id integer PRIMARY KEY,
  day_id integer PRIMARY KEY,
  opening_time text,
  closing_time text
);
CREATE TABLE Checkins (
  business_id integer PRIMARY KEY,
  day_id integer PRIMARY KEY,
  label_time_0 text,
  label_time_1 text,
  label_time_2 text,
  label_time_3 text,
  label_time_4 text,
  label_time_5 text,
  label_time_6 text,
  label_time_7 text,
  label_time_8 text,
  label_time_9 text,
  label_time_10 text,
  label_time_11 text,
  label_time_12 text,
  label_time_13 text,
  label_time_14 text,
  label_time_15 text,
  label_time_16 text,
  label_time_17 text,
  label_time_18 text,
  label_time_19 text,
  label_time_20 text,
  label_time_21 text,
  label_time_22 text,
  label_time_23 text
);
CREATE TABLE Elite (
  user_id integer PRIMARY KEY,
  year_id integer PRIMARY KEY
);
CREATE TABLE Reviews (
  business_id integer PRIMARY KEY,
  user_id integer PRIMARY KEY,
  review_stars integer,
  review_votes_funny text,
  review_votes_useful text,
  review_votes_cool text,
  review_length text
);
CREATE TABLE Tips (
  business_id integer PRIMARY KEY,
  user_id integer PRIMARY KEY,
  likes integer,
  tip_length text
);
CREATE TABLE Users_Compliments (
  compliment_id integer PRIMARY KEY,
  user_id integer PRIMARY KEY,
  number_of_compliments text
);
CREATE TABLE Business (
  business_id integer PRIMARY KEY,
  active text,
  city text,
  state text,
  stars real,
  review_count text
);
CREATE TABLE Users (
  user_id integer PRIMARY KEY,
  user_yelping_since_year integer,
  user_average_stars text,
  user_votes_funny text,
  user_votes_useful text,
  user_votes_cool text,
  user_review_count text,
  user_fans text
);

Hint: Sunday refers to day_of_week = 'Sunday' where day_id = 1; opened from 9AM to 9PM refers to Business_Hours where opening_time = '9AM' and closing_time = '9PM'; DIVIDE(COUNT(opening_time = '9AM' and closing_time = '9PM' and day_of_week = 'Sunday'), COUNT(opening_time = NOT NULL and closing_time = NOT NULL and day_of_week = 'Sunday')) as percentage;

Question: Calculate the percentage of business which opened on Sunday from 9AM to 9PM based on the number of business opened on Sunday.

assistant: SELECT CAST(SUM(CASE WHEN T2.opening_time = '9AM' AND T2.closing_time = '9PM' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(T1.day_id) FROM Days AS T1 INNER JOIN Business_Hours AS T2 ON T1.day_id = T2.day_id WHERE T1.day_of_week = 'Sunday'