mereenfant by month

select concat(mother_city_code,'/',mother_hospital_code) as hospital, count(id_patient) as nbr, concat(month(infant_dob),'-',year(infant_dob)) as month_year_dob
from testing_mereenfant
where infant_dob between '2017-08-01' and '2018-08-31'
GROUP BY concat(month(infant_dob),'-',year(infant_dob)), concat(mother_city_code,'/',mother_hospital_code)
order by concat(mother_city_code,'/',mother_hospital_code)