With SQL, how to achieve the following goal

gistfile1.txt

CREATE TABLE `users` (
  `id` int(11) DEFAULT NULL,
  `email` varchar(255) CHARACTER SET latin1 DEFAULT NULL,
  `born_at` varchar(255) CHARACTER SET latin1 DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

INSERT INTO `users` (`id`,`email`,`born_at`) VALUES ('1','same@example.com','1980-01-01');
INSERT INTO `users` (`id`,`email`,`born_at`) VALUES ('2','2@example.com','1980-01-02');
INSERT INTO `users` (`id`,`email`,`born_at`) VALUES ('3','3@example.com','1980-01-01');
INSERT INTO `users` (`id`,`email`,`born_at`) VALUES ('4','4@example.com','1980-01-03');
INSERT INTO `users` (`id`,`email`,`born_at`) VALUES ('5','same@example.com','1980-01-02');
INSERT INTO `users` (`id`,`email`,`born_at`) VALUES ('6','same@example.com','1980-01-02');



# Desired format
# count_with_similar_born_at_but_different_email born_at
2 1980-01-01
2 1980-01-02
1 1980-01-03

Solution : SELECT born_at, COUNT(DISTINCT(email)) FROM users GROUP BY born_at