MySQL 8.0

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drop table if exists aa;
create table aa(`Country` varchar(100),`Month_Year` varchar(100),
                `created_at` timestamp NOT NULL DEFAULT current_timestamp());
insert into aa(Country,Month_Year,created_at) 
    values('Spain1','JUN2020','2020-09-03 14:20:20'), 
            ('Spain2','JUN2020','2020-09-03 14:20:20'),
            ('Spain3','JUN2020','2020-08-03 14:20:20'),
            ('Spain4','JUN2020','2020-07-03 14:20:20'),
            ('Spain5','JUN2020','2020-06-03 14:20:20'),
            ('Spain6','JUL2020','2020-09-01 14:20:20'),
            ('Spain7','JUL2020','2020-09-03 14:20:20'),
            ('Spain8','JUN2020','2020-09-03 14:20:20'),
            ('Spain9','AUG2020','2020-09-01 14:20:20'),
            ('Spain10','AUG2020','2020-05-03 14:20:20'),
            ('Spain11','AUG2020','2020-05-03 14:20:20'),
            ('Porto1','AUG2019','2020-05-03 14:20:20'),
            ('Porto2','AUG2019','2020-05-03 14:20:20'),
            ('Porto2','AUG2019','2020-05-03 13:20:20'),
            ('Porto2','AUG2011','2020-05-03 13:20:20');
select * from aa;

Country	Month_Year	created_at
Spain1	JUN2020	2020-09-03 14:20:20
Spain2	JUN2020	2020-09-03 14:20:20
Spain3	JUN2020	2020-08-03 14:20:20
Spain4	JUN2020	2020-07-03 14:20:20
Spain5	JUN2020	2020-06-03 14:20:20
Spain6	JUL2020	2020-09-01 14:20:20
Spain7	JUL2020	2020-09-03 14:20:20
Spain8	JUN2020	2020-09-03 14:20:20
Spain9	AUG2020	2020-09-01 14:20:20
Spain10	AUG2020	2020-05-03 14:20:20
Spain11	AUG2020	2020-05-03 14:20:20
Porto1	AUG2019	2020-05-03 14:20:20
Porto2	AUG2019	2020-05-03 14:20:20
Porto2	AUG2019	2020-05-03 13:20:20
Porto2	AUG2011	2020-05-03 13:20:20

Country	Month_Year	created_at
Spain1	JUN2020	2020-09-03 14:20:20
Spain2	JUN2020	2020-09-03 14:20:20
Spain7	JUL2020	2020-09-03 14:20:20
Spain8	JUN2020	2020-09-03 14:20:20
Spain9	AUG2020	2020-09-01 14:20:20
Porto1	AUG2019	2020-05-03 14:20:20
Porto2	AUG2019	2020-05-03 14:20:20
Porto2	AUG2011	2020-05-03 13:20:20