text: DROP PROCEDURE IF EXISTS `proc_get_national_testing_trends`;
  DELIMITER //
  CREATE PROCEDURE `proc_get_national_testing_trends`
  (IN from_year INT(11), IN to_year INT(11))
  BEGIN
    SET @QUERY =    "SELECT 
              `year`, 
              `month`, 
              `pos`, 
              `neg` 
              FROM `national_summary`
                  WHERE 1";
  
      SET @QUERY = CONCAT(@QUERY, " AND `year` = '",from_year,"' OR `year` = '",to_year,"' ORDER BY `year` ASC, `month` ");
      
      PREPARE stmt FROM @QUERY;
      EXECUTE stmt;
  END //
  DELIMITER ;
  