SELECT COUNT(DISTINCT user_id) * 100.0 / (SELECT COUNT(DISTINCT user_id) FROM table_name WHERE DATE(user_signup_date) = ‘2023-01-01’) AS retention_rate FROM table_name WHERE DATE(event_date) = ‘2023-01-08’ AND user_id IN (SELECT user_id FROM table_name WHERE DATE(user_signup_date) = ‘2023-01-01’)