select year(date_blood_taken),
count(id) as total,
sum(which_pcr=1) as pcr_1,
sum(which_pcr=5) as pcr_n,
sum(timestampdiff(week, date_of_birth, date_blood_taken)<=8) as under_8_weeks,
sum(pcr_result=1) as positif
 from testing_specimen where year(date_blood_taken)>=2015 and date_blood_taken<='2017-06-30'
 group by year(date_blood_taken)